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MBHSM101QUENCH PROTECTION STUDIES
Susana Izquierdo Bermudez
With many contributions from Juho Rysti Gerard Willering and all the people involved in the manufacturing and test of the magnet
25-07-2014
2Susana Izquierdo Bermudez
General magnet parameters
0 2 4 6 8 10 12 14 160
2
4
6
8
10
12
14
16
18
20VAMAS 1 - XS 19 K
VAMAS 2 - XS 19 K
Param XS 19 K
VAMAS 1 - XS 43 K
Param XS 43 K
VAMAS 2 - XS 43 K
Loadline Roxie 2D w SF
Loadline Roxie 3D w SF
Magnetic field [T]
Cabl
e cu
rren
t [k
A]
Identification MBSMH101 Coil 101 ndash Copper coil Coil 105 ndash OST RRP 108127 Ta-Dopedbull ODS alloy wedges (Oxide Dispersion
Strengthening ) bull CERN V4 end spacers SLS (Selective
Laser Sintering) with springy legs - hinge
bull Metallic saddles and splice blocks bull External trace glued on coil OD
carrying V-taps and quench heaters
Short sample current limits 43 K 1515 kA plusmn 1 19 K 1669 kA plusmn 1
Peak field is at the ends The short sample limit is about 11-12kA higher for the straight section In all the plots linked to quench heater delay the 2D short sample limit is considered (because the quench heaters are in the straight section)
More infohellip httpindicocernchevent331147
3Susana Izquierdo Bermudez
Overview QH design
More details can be found in httpsindicocernchevent311824
Main featuresbull Stainless steel 25 microm thick partially plated with 5 microm
thick layer of copper to reduce their overall resistance (design suitable for 55 m length)
bull Heating stations are 19 mm wide in the mid-plane (LF) and 24 mm wide in pole area (HF)
bull The distance in between non-plated sections is 90 mm in the LF and 130 mm in the HF where quench propagation is faster in the longitudinal direction
bull The heaters are embedded in between two layers of polyimide insulation foils The thickness of the insulation between the heater and the coil is composed of 0050 mm of polyimide about 0025 mm of Epoxy glue plus the additions S2 glass added to the coil outer radius during impregnation
bull The trace is then glued to the coil and compressed radially during collaring to about 40 MPa
Coverage Distance between stations
wid
th
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x05 mm kapton (ground insulation)
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
4Susana Izquierdo Bermudez
Trace manufacturing and characterizationbull Resistance measurements at RT and 77 K
bull Stainless steel stations Measured resistance close to expected values bull 3 difference at RTbull 8 difference at 77K
bull Copper regions Measured resistance higher than expected value
bull 20 difference at RTbull 25 difference at 77K
bull High current testbull No degradation was observed in the bonding
bull Temperature cycling at 77 Kbull No degradation
1 2 3 4 50
10
20
30
40
50
60
70
80
90 Resistance RT HF_CopperHF_Stainless SteelLF_CopperLF_Stainless SteelHF_Copper ExpectedLF_Copper ExpectedHF_Stainless Steel ExpectedLF_Stainless Steel ExpectedLF_Copper Expected if 4 umHF_Copeer Expected if 4 um
Measurement
Res
ista
nce
(m
Oh
ms)
Kapton (50 microm)Glue (lt25 microm)Stainless Steel (25 microm)Copper (5 microm) Glue (50 microm)
Kapton (25 microm)
Trace stack for 11T
ρss=7310-7Ωm RRRSS=134 ρss=1810-8Ωm RRRSS=30
5Susana Izquierdo Bermudez
Before trace installationbull Resistance measurements at RT
bull High voltage test to ground under 20-30 MPa pressure (2kV)
After trace installation every step of the manufacturing process
Expected value R1=R2=165 ΩMeasured value asymp 17 Ω
bull Resistancebull QH to ground and QH to coil (1 kV)bull Discharge test (pulse) Low thermal load to
the heaters (under adiabatic conditions and assuming constant material properties peak current defined to limit the temperature increase to 50 K) (only in the manufacturing steps after collaring)
Trace QA
6Susana Izquierdo Bermudez
QH test set up in SM18bull ldquoStandardrdquo LHC Quench Heater Power Supply V =
450 V C=705 mFbull Maximum current = 150 Abull Voltage is fixed to a total of 900 V additional
resistance in series with the circuit is setting the current
bull Three different current levels in the heaters were explored 80 A 100 A and 150 A
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
RLF
RHF
Radd
CE+
-
Circuit 1 Circuit 2
Cu
Nb3Sn
I[A]
PLF
[Wcm2]PHF [Wcm2]
Pave [Wcm2]
RC (ms)
80 413 259 34 80
100 645 404 52 64
150 1451 910 118 42
7Susana Izquierdo Bermudez
QH test set up in SM18
10 kA
65 kA
13 kA
Quench heater provoked quench performed at different magnet current levels from 6 kA to 14 kA
We studybull QH delaybull QH efficiencybull Transversal heat propagation
8Susana Izquierdo Bermudez
Quench Heater Delay
2 times to look atbull Quench heater onset start of the quenchbull Quench heater efficient time where slope of the resistive voltage cross the horizontal axis
Gerard Willering
What we define as quench heater delay
28 ms 35 ms18 ms 21ms
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
2Susana Izquierdo Bermudez
General magnet parameters
0 2 4 6 8 10 12 14 160
2
4
6
8
10
12
14
16
18
20VAMAS 1 - XS 19 K
VAMAS 2 - XS 19 K
Param XS 19 K
VAMAS 1 - XS 43 K
Param XS 43 K
VAMAS 2 - XS 43 K
Loadline Roxie 2D w SF
Loadline Roxie 3D w SF
Magnetic field [T]
Cabl
e cu
rren
t [k
A]
Identification MBSMH101 Coil 101 ndash Copper coil Coil 105 ndash OST RRP 108127 Ta-Dopedbull ODS alloy wedges (Oxide Dispersion
Strengthening ) bull CERN V4 end spacers SLS (Selective
Laser Sintering) with springy legs - hinge
bull Metallic saddles and splice blocks bull External trace glued on coil OD
carrying V-taps and quench heaters
Short sample current limits 43 K 1515 kA plusmn 1 19 K 1669 kA plusmn 1
Peak field is at the ends The short sample limit is about 11-12kA higher for the straight section In all the plots linked to quench heater delay the 2D short sample limit is considered (because the quench heaters are in the straight section)
More infohellip httpindicocernchevent331147
3Susana Izquierdo Bermudez
Overview QH design
More details can be found in httpsindicocernchevent311824
Main featuresbull Stainless steel 25 microm thick partially plated with 5 microm
thick layer of copper to reduce their overall resistance (design suitable for 55 m length)
bull Heating stations are 19 mm wide in the mid-plane (LF) and 24 mm wide in pole area (HF)
bull The distance in between non-plated sections is 90 mm in the LF and 130 mm in the HF where quench propagation is faster in the longitudinal direction
bull The heaters are embedded in between two layers of polyimide insulation foils The thickness of the insulation between the heater and the coil is composed of 0050 mm of polyimide about 0025 mm of Epoxy glue plus the additions S2 glass added to the coil outer radius during impregnation
bull The trace is then glued to the coil and compressed radially during collaring to about 40 MPa
Coverage Distance between stations
wid
th
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x05 mm kapton (ground insulation)
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
4Susana Izquierdo Bermudez
Trace manufacturing and characterizationbull Resistance measurements at RT and 77 K
bull Stainless steel stations Measured resistance close to expected values bull 3 difference at RTbull 8 difference at 77K
bull Copper regions Measured resistance higher than expected value
bull 20 difference at RTbull 25 difference at 77K
bull High current testbull No degradation was observed in the bonding
bull Temperature cycling at 77 Kbull No degradation
1 2 3 4 50
10
20
30
40
50
60
70
80
90 Resistance RT HF_CopperHF_Stainless SteelLF_CopperLF_Stainless SteelHF_Copper ExpectedLF_Copper ExpectedHF_Stainless Steel ExpectedLF_Stainless Steel ExpectedLF_Copper Expected if 4 umHF_Copeer Expected if 4 um
Measurement
Res
ista
nce
(m
Oh
ms)
Kapton (50 microm)Glue (lt25 microm)Stainless Steel (25 microm)Copper (5 microm) Glue (50 microm)
Kapton (25 microm)
Trace stack for 11T
ρss=7310-7Ωm RRRSS=134 ρss=1810-8Ωm RRRSS=30
5Susana Izquierdo Bermudez
Before trace installationbull Resistance measurements at RT
bull High voltage test to ground under 20-30 MPa pressure (2kV)
After trace installation every step of the manufacturing process
Expected value R1=R2=165 ΩMeasured value asymp 17 Ω
bull Resistancebull QH to ground and QH to coil (1 kV)bull Discharge test (pulse) Low thermal load to
the heaters (under adiabatic conditions and assuming constant material properties peak current defined to limit the temperature increase to 50 K) (only in the manufacturing steps after collaring)
Trace QA
6Susana Izquierdo Bermudez
QH test set up in SM18bull ldquoStandardrdquo LHC Quench Heater Power Supply V =
450 V C=705 mFbull Maximum current = 150 Abull Voltage is fixed to a total of 900 V additional
resistance in series with the circuit is setting the current
bull Three different current levels in the heaters were explored 80 A 100 A and 150 A
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
RLF
RHF
Radd
CE+
-
Circuit 1 Circuit 2
Cu
Nb3Sn
I[A]
PLF
[Wcm2]PHF [Wcm2]
Pave [Wcm2]
RC (ms)
80 413 259 34 80
100 645 404 52 64
150 1451 910 118 42
7Susana Izquierdo Bermudez
QH test set up in SM18
10 kA
65 kA
13 kA
Quench heater provoked quench performed at different magnet current levels from 6 kA to 14 kA
We studybull QH delaybull QH efficiencybull Transversal heat propagation
8Susana Izquierdo Bermudez
Quench Heater Delay
2 times to look atbull Quench heater onset start of the quenchbull Quench heater efficient time where slope of the resistive voltage cross the horizontal axis
Gerard Willering
What we define as quench heater delay
28 ms 35 ms18 ms 21ms
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
3Susana Izquierdo Bermudez
Overview QH design
More details can be found in httpsindicocernchevent311824
Main featuresbull Stainless steel 25 microm thick partially plated with 5 microm
thick layer of copper to reduce their overall resistance (design suitable for 55 m length)
bull Heating stations are 19 mm wide in the mid-plane (LF) and 24 mm wide in pole area (HF)
bull The distance in between non-plated sections is 90 mm in the LF and 130 mm in the HF where quench propagation is faster in the longitudinal direction
bull The heaters are embedded in between two layers of polyimide insulation foils The thickness of the insulation between the heater and the coil is composed of 0050 mm of polyimide about 0025 mm of Epoxy glue plus the additions S2 glass added to the coil outer radius during impregnation
bull The trace is then glued to the coil and compressed radially during collaring to about 40 MPa
Coverage Distance between stations
wid
th
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x05 mm kapton (ground insulation)
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
4Susana Izquierdo Bermudez
Trace manufacturing and characterizationbull Resistance measurements at RT and 77 K
bull Stainless steel stations Measured resistance close to expected values bull 3 difference at RTbull 8 difference at 77K
bull Copper regions Measured resistance higher than expected value
bull 20 difference at RTbull 25 difference at 77K
bull High current testbull No degradation was observed in the bonding
bull Temperature cycling at 77 Kbull No degradation
1 2 3 4 50
10
20
30
40
50
60
70
80
90 Resistance RT HF_CopperHF_Stainless SteelLF_CopperLF_Stainless SteelHF_Copper ExpectedLF_Copper ExpectedHF_Stainless Steel ExpectedLF_Stainless Steel ExpectedLF_Copper Expected if 4 umHF_Copeer Expected if 4 um
Measurement
Res
ista
nce
(m
Oh
ms)
Kapton (50 microm)Glue (lt25 microm)Stainless Steel (25 microm)Copper (5 microm) Glue (50 microm)
Kapton (25 microm)
Trace stack for 11T
ρss=7310-7Ωm RRRSS=134 ρss=1810-8Ωm RRRSS=30
5Susana Izquierdo Bermudez
Before trace installationbull Resistance measurements at RT
bull High voltage test to ground under 20-30 MPa pressure (2kV)
After trace installation every step of the manufacturing process
Expected value R1=R2=165 ΩMeasured value asymp 17 Ω
bull Resistancebull QH to ground and QH to coil (1 kV)bull Discharge test (pulse) Low thermal load to
the heaters (under adiabatic conditions and assuming constant material properties peak current defined to limit the temperature increase to 50 K) (only in the manufacturing steps after collaring)
Trace QA
6Susana Izquierdo Bermudez
QH test set up in SM18bull ldquoStandardrdquo LHC Quench Heater Power Supply V =
450 V C=705 mFbull Maximum current = 150 Abull Voltage is fixed to a total of 900 V additional
resistance in series with the circuit is setting the current
bull Three different current levels in the heaters were explored 80 A 100 A and 150 A
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
RLF
RHF
Radd
CE+
-
Circuit 1 Circuit 2
Cu
Nb3Sn
I[A]
PLF
[Wcm2]PHF [Wcm2]
Pave [Wcm2]
RC (ms)
80 413 259 34 80
100 645 404 52 64
150 1451 910 118 42
7Susana Izquierdo Bermudez
QH test set up in SM18
10 kA
65 kA
13 kA
Quench heater provoked quench performed at different magnet current levels from 6 kA to 14 kA
We studybull QH delaybull QH efficiencybull Transversal heat propagation
8Susana Izquierdo Bermudez
Quench Heater Delay
2 times to look atbull Quench heater onset start of the quenchbull Quench heater efficient time where slope of the resistive voltage cross the horizontal axis
Gerard Willering
What we define as quench heater delay
28 ms 35 ms18 ms 21ms
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
4Susana Izquierdo Bermudez
Trace manufacturing and characterizationbull Resistance measurements at RT and 77 K
bull Stainless steel stations Measured resistance close to expected values bull 3 difference at RTbull 8 difference at 77K
bull Copper regions Measured resistance higher than expected value
bull 20 difference at RTbull 25 difference at 77K
bull High current testbull No degradation was observed in the bonding
bull Temperature cycling at 77 Kbull No degradation
1 2 3 4 50
10
20
30
40
50
60
70
80
90 Resistance RT HF_CopperHF_Stainless SteelLF_CopperLF_Stainless SteelHF_Copper ExpectedLF_Copper ExpectedHF_Stainless Steel ExpectedLF_Stainless Steel ExpectedLF_Copper Expected if 4 umHF_Copeer Expected if 4 um
Measurement
Res
ista
nce
(m
Oh
ms)
Kapton (50 microm)Glue (lt25 microm)Stainless Steel (25 microm)Copper (5 microm) Glue (50 microm)
Kapton (25 microm)
Trace stack for 11T
ρss=7310-7Ωm RRRSS=134 ρss=1810-8Ωm RRRSS=30
5Susana Izquierdo Bermudez
Before trace installationbull Resistance measurements at RT
bull High voltage test to ground under 20-30 MPa pressure (2kV)
After trace installation every step of the manufacturing process
Expected value R1=R2=165 ΩMeasured value asymp 17 Ω
bull Resistancebull QH to ground and QH to coil (1 kV)bull Discharge test (pulse) Low thermal load to
the heaters (under adiabatic conditions and assuming constant material properties peak current defined to limit the temperature increase to 50 K) (only in the manufacturing steps after collaring)
Trace QA
6Susana Izquierdo Bermudez
QH test set up in SM18bull ldquoStandardrdquo LHC Quench Heater Power Supply V =
450 V C=705 mFbull Maximum current = 150 Abull Voltage is fixed to a total of 900 V additional
resistance in series with the circuit is setting the current
bull Three different current levels in the heaters were explored 80 A 100 A and 150 A
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
RLF
RHF
Radd
CE+
-
Circuit 1 Circuit 2
Cu
Nb3Sn
I[A]
PLF
[Wcm2]PHF [Wcm2]
Pave [Wcm2]
RC (ms)
80 413 259 34 80
100 645 404 52 64
150 1451 910 118 42
7Susana Izquierdo Bermudez
QH test set up in SM18
10 kA
65 kA
13 kA
Quench heater provoked quench performed at different magnet current levels from 6 kA to 14 kA
We studybull QH delaybull QH efficiencybull Transversal heat propagation
8Susana Izquierdo Bermudez
Quench Heater Delay
2 times to look atbull Quench heater onset start of the quenchbull Quench heater efficient time where slope of the resistive voltage cross the horizontal axis
Gerard Willering
What we define as quench heater delay
28 ms 35 ms18 ms 21ms
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
5Susana Izquierdo Bermudez
Before trace installationbull Resistance measurements at RT
bull High voltage test to ground under 20-30 MPa pressure (2kV)
After trace installation every step of the manufacturing process
Expected value R1=R2=165 ΩMeasured value asymp 17 Ω
bull Resistancebull QH to ground and QH to coil (1 kV)bull Discharge test (pulse) Low thermal load to
the heaters (under adiabatic conditions and assuming constant material properties peak current defined to limit the temperature increase to 50 K) (only in the manufacturing steps after collaring)
Trace QA
6Susana Izquierdo Bermudez
QH test set up in SM18bull ldquoStandardrdquo LHC Quench Heater Power Supply V =
450 V C=705 mFbull Maximum current = 150 Abull Voltage is fixed to a total of 900 V additional
resistance in series with the circuit is setting the current
bull Three different current levels in the heaters were explored 80 A 100 A and 150 A
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
RLF
RHF
Radd
CE+
-
Circuit 1 Circuit 2
Cu
Nb3Sn
I[A]
PLF
[Wcm2]PHF [Wcm2]
Pave [Wcm2]
RC (ms)
80 413 259 34 80
100 645 404 52 64
150 1451 910 118 42
7Susana Izquierdo Bermudez
QH test set up in SM18
10 kA
65 kA
13 kA
Quench heater provoked quench performed at different magnet current levels from 6 kA to 14 kA
We studybull QH delaybull QH efficiencybull Transversal heat propagation
8Susana Izquierdo Bermudez
Quench Heater Delay
2 times to look atbull Quench heater onset start of the quenchbull Quench heater efficient time where slope of the resistive voltage cross the horizontal axis
Gerard Willering
What we define as quench heater delay
28 ms 35 ms18 ms 21ms
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
6Susana Izquierdo Bermudez
QH test set up in SM18bull ldquoStandardrdquo LHC Quench Heater Power Supply V =
450 V C=705 mFbull Maximum current = 150 Abull Voltage is fixed to a total of 900 V additional
resistance in series with the circuit is setting the current
bull Three different current levels in the heaters were explored 80 A 100 A and 150 A
50 60 70 80 90 10011012013014015000
200400600800
100012001400160018002000 Low Field Region
High Field Region
Heater Current (A)
Po
wer
den
sity
(W
cm
2)
RLF
RHF
Radd
CE+
-
Circuit 1 Circuit 2
Cu
Nb3Sn
I[A]
PLF
[Wcm2]PHF [Wcm2]
Pave [Wcm2]
RC (ms)
80 413 259 34 80
100 645 404 52 64
150 1451 910 118 42
7Susana Izquierdo Bermudez
QH test set up in SM18
10 kA
65 kA
13 kA
Quench heater provoked quench performed at different magnet current levels from 6 kA to 14 kA
We studybull QH delaybull QH efficiencybull Transversal heat propagation
8Susana Izquierdo Bermudez
Quench Heater Delay
2 times to look atbull Quench heater onset start of the quenchbull Quench heater efficient time where slope of the resistive voltage cross the horizontal axis
Gerard Willering
What we define as quench heater delay
28 ms 35 ms18 ms 21ms
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
7Susana Izquierdo Bermudez
QH test set up in SM18
10 kA
65 kA
13 kA
Quench heater provoked quench performed at different magnet current levels from 6 kA to 14 kA
We studybull QH delaybull QH efficiencybull Transversal heat propagation
8Susana Izquierdo Bermudez
Quench Heater Delay
2 times to look atbull Quench heater onset start of the quenchbull Quench heater efficient time where slope of the resistive voltage cross the horizontal axis
Gerard Willering
What we define as quench heater delay
28 ms 35 ms18 ms 21ms
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
8Susana Izquierdo Bermudez
Quench Heater Delay
2 times to look atbull Quench heater onset start of the quenchbull Quench heater efficient time where slope of the resistive voltage cross the horizontal axis
Gerard Willering
What we define as quench heater delay
28 ms 35 ms18 ms 21ms
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
9Susana Izquierdo Bermudez
Quench Heater Delay
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
Hea
ter
Del
ay [
ms]
T = 19 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]H
eate
r D
ela
y [m
s]
T = 42 K
32 Wcm2 QO
32 Wcm2 QE
52 Wcm2 QO
52 Wcm2 QE
118 Wcm2 QO
118 Wcm2 QE
Large difference between ldquoQuench Onset (QO)rdquo and ldquoQuench heater efficient (QE)rdquo at low currents
From now on if not specified heater delays plotted correspond to the ldquoQuench Onsetrdquo and not ldquoQuench Efficientrdquo
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
10Susana Izquierdo Bermudez
Comparison to FNAL 11T dipoles
40 50 60 70 80 90 10020
30
40
50
60
II2Dss
[]
Hea
ter
De
lay
[ms]
43 K 52 Wcm2 RC=64ms
19 K 52 Wcm2 RC=64ms
43 K 34 Wcm2 RC=118ms
19 K 34 Wcm2 RC=118ms
MBHSM101
FNAL MBHSM insulation between heater and coilbull 0125 mm of glass on the outer impregnated with the coilbull 0125 mm of kapton between heater and coil
CERN MBHSM101insulation between heater and coilbull 0200-0250 mm of glass on the outer impregnated with the coilbull 0050 mm of kapton between heater and coil + about 0025 mm glue
FNAL data from httpsindicocernchevent311824Slides from Guram Chlachidze
Heater delays are very close to delays measured in FNAL
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
11Susana Izquierdo Bermudez
Comparison to HQ
20 40 60 80 1000
20
40
60
II2Dss
[]
He
ater
Del
ay [
ms]
Pave
=52 Wcm2 RC=64ms
MBHSM101 43 KMBHSM101 19 K
HQ data data from httpsindicocernchevent311824Slides from Tiina Slami
Significant longer delays than in HQ Main difference in the case of 11T heaters are glued on top of the coil after impregnation
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
12Susana Izquierdo Bermudez
Comparison to modelled delays
02 mm S2 glass0025+ mm glue + 0050 mm kapton
QUENCH HEATERS4x0125 mm kapton (ground insulation)
Juho Rysti
bull Model by Juho Rysti using the commercial software COMSOLbull Basis of the model are the same as Tiinarsquos model (https
indicocernchevent311824)bull Quench heater delays modelled for different thickness of S2 glass between coil
and heaters Nominal should be close to 03 mm
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
13Susana Izquierdo Bermudez
Comparison to modelled delays
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
Hea
ter
Dela
y [m
s]
118 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
10
20
30
40
50
60
70
80
II2Dss
[]
He
ate
r D
ela
y [m
s]
118 Wcm2 T = 43 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
Hea
ter
Dela
y [m
s]
52 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
30 40 50 60 70 800
20
40
60
80
100
120
II2Dss
[]
He
ate
r D
ela
y [m
s]
32 Wcm2 T = 19 K
QOQE02 mm025 mm03 mm
QO Quench OnsetQE Quench Efficient
Juho Rysti
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
14Susana Izquierdo Bermudez
Transverse heat propagation
40 45 50 55 60 65 70 75 80
-20
0
20
40
60
80
100
B1-B5 B2 - B6 B3-B6
IIss2D []
del
ay (
ms)
4 32
1
6
5
Measured propagation consistent with previous FNAL measurements
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
15Susana Izquierdo Bermudez
Modelling heat propagation within the coil
iadjiJouleij
ijijk
ikk
k
ikkk qqqTTH
x
TkA
xt
TCA
Two principal directions 1 Longitudinal Length scale is hundreds of m2 TransverseLength scale is tenths of mm
Power exchanged between components in the conductor
Joule heating
External heat perturbation
The conductor is a continuum solved with accurate (high order) and adaptive (front tracking) methods
Longitudinal Transverse
Power exchange between adjacent conductors
2nd order thermal network explicitly coupling with the 1D longitudinal model
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
16Susana Izquierdo Bermudez
Modelling heat propagation within the coilbull We are focused on the modelling of the thermal transient process the hot spot
temperature for the same MIITs can be very different depending in the time transient
000 002 004 006 008 010 012 014 016 018 0200
2
4
6
8
10
12
14
0
50
100
150
200
250
300
Case 1 I
Case 2 I
Case 3 I
Case 1 T
Case 2 T
Case 3 T
Time (s)
Cu
rre
nt
I [
kA
]
Tm
ax
[K
]bull Main simplifications
bull Constant inductancebull Heat transfer from heater to coil is not included in the model Quench
heaters are modelled as a heat source applied directly on the cablebull AC loss not included in the model
Hot spot temperature for different current decays but with the same QI (13 MIITs)
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
17Susana Izquierdo Bermudez
Model vs Experimental
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 140
10
20
30
40
50
60
70
80
90MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
8 9 10 11 12 13 14-20
-10
0
10
20
30
40
50
60
70
80MEASUREDIL = 0 mmIL = 05 mm
I (kA)
del
ay (
ms)
Block 5 Block 1 Block 6 Block 2 Block 6 Block 3
Nominal inter-layer thickness 05 mm
Points at 14 kA not representative because the quench was starting in the layer jump and not under the heaters
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
Susana Izquierdo Bermudez
Current decay and resistance growth
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
62
64
66
68
7
72
74
76
78
8
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
65
7
75
8
85
9
95
10
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time msI
kA
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0156
7
8
9
10
11
12
time ms
I k
A
QH effective
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time ms
R
mO
hm
QH delay
ExperimentalIL=0mmIL=05mm
0 005 01 0150
5
10
15
20
25
30
35
40
45
50
time msR
m
Oh
m
QH effective
ExperimentalIL=0mmIL=05mm
8 kA
8 kA
10 kA
10 kA
12 kA
12 kA
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
19Susana Izquierdo Bermudez
Some comments and remarksModelled resistance growth gets closer to experimental values when the thickness of the inter layer is set to 0 mm and only the cable insulation is considered This can be a combination of different effectsbull AC loss is not considered bull Second order thermal network is not ldquofully
catchingrdquo the thermal diffusion process in the insulation
bull Uncertanties in the material properties of the insulation
The model does not account for heater stations it assumes that the entire cable length is covered by the heaters The relative good agreement with the experimental value is an indication that the heater stations are effective
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
20Susana Izquierdo Bermudez
Longitudinal propagation and TmaxExperimental data from Hugo Bajas
Not specific studies on hot spot temperature and longitudinal propagation in MBHSM101 but analysis were performed in SMC using 11T cable
More detailshttpsindicocernchevent311824
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
21Susana Izquierdo Bermudez
Conclusions and final remarksbull An effort is on going in order to understand the thermodynamic process during
quench Model validation is on going
bull Thermal conductivity in the insulation plays a key role and a better knowledge of these properties is important
bull We are using G10 material properties for the insulation Does anyone have measurementsgood reference for actual coils using the same resin reaction treatment ceramic binder hellip
bull Based on the measurements and model QH delay for the real 11T magnet should be about 20 ms at 80 of the short sample limit If we set the MIITs limit to 17 MA2s this is 25 of our total budget it is a lot
bull Shorter delay is expected if the heater is impregnated with the coil
bull A redundant system with only outer layer heaters seems more than challenging
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
Additional slides
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
23Susana Izquierdo Bermudez
TRAINING
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
24Susana Izquierdo Bermudez
Is the long QH delay at low current a killer
30 40 50 60 70 800
20
40
60
80
100
II2Dss
[]
He
ater
Del
ay [
ms]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
30 40 50 60 70 800
2
4
6
8
10
12
14
16
18
20
II2Dss
[]
He
ate
r D
ela
y [m
s]
34 Wcm2-118 Wcm2
52 Wcm2-118 Wcm2
Additional Budget
Defining the additional budget as the time we can stay at a certain current to achieve the same MIITs that at 80Iss one can see that even if the delays are becoming much longer at low current level at lower quench heater current density the situation is more critical at higher current levels This is only partially true because the additional time to detect the quench at lower current level is not included
119860119889119889119894119905119894119900119899119886119897 119861119906119889119892119890119905 ( 119868 )=08 119868119904119904 ∙119905 08 119868119904119904
119868minus119905 08119868119904119904
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
25Susana Izquierdo Bermudez
MB vs 11T
Parameter MB 11T
Magnet
MIITs to reach 400 K 8T MA2s 52 18
Temperature margin LF 4 8-9
Temperature margin HF 3-4 5-9
Differential Inductance mHm 69 117
Stored energy kJm 567 897
Quench heater
circuit
Operational voltage V 450 450
Peak Current A 85 110-120
Maximum stored energy kJ 286 25 - 35
Time constant ms 75 55-72
Quench Heater Pattern 400 mm plated120 mm un-plated
90-140 mm plated50 mm un-plated
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
26Susana Izquierdo Bermudez
Cable Parameters
Parameter Value Cable width mm 14847 Cable mid thickness mm 1307 Strand diameter mm 07 No of strands 40 CuSc ratio 1106 Insulation thicknessmm 01 Total cable area mm2 22676 Total strand area mm2 15394 Cu area mm2 8084 SC area Nb3Sn mm2 7310 Insulation area G10 mm2 3271 Void area filled with epoxy mm2 4011 Cu RRR 100
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
27Susana Izquierdo Bermudez
Protection System LHC Magnets
The Protection System for the Superconducting Elements of the Large Hadron Collider at CERNK Dahlerup-Petersen1 R Denz1 JL Gomez-Costa1 D Hagedorn1 P Proudlock1 F Rodriguez-Mateos1 R Schmidt1 and F Sonnemann2
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
28Susana Izquierdo Bermudez
STANDARD LHC HEATER POWER SUPPLIES
bull Supply based on the thyristor-triggered discharge of aluminium electrolytic capacitorsbull Each power supply contains a bank with 6 capacitors (47 mF500V) where two sets of 3
parallel capacitors are connected in series total capacitance 705 mF
bull Nominal operating voltage 450 V (90 of the maximum voltage)bull OPERATION Peak current about 85 A giving a maximum stored energy of 286 kJ
Actual limitations in terms of current bull Power supply equipped with two SKT8018E type thyristors rated for 80 A at 85 ˚C bull Maximum current for continuous operation = 135 Abull Peak current at 25 ˚C for 10 ms =1700 A (it will probably destroy the PCB of the power supply)bull Can be safely operated up to 300 A (resistive load in LHC from 12Ω in most of the circuits to
31 Ω in some systems such as D1 protection )
QUENCH HEATER EXPERIMENTS ON THE LHC MAIN SUPERCONDUCTING MAGNETSF Rodriguez-Mateos P PugnatS Sanfilippo R Schmidt A Siemko F Sonnemann
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
29Susana Izquierdo Bermudez
Kapton G10
The
rmal
co
nduc
tivity
Hea
t ca
paci
ty
httpsespacecernchroxieDocumentationMaterialspdf
Insulation MP
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
30Susana Izquierdo Bermudez
Insulation MP
0 5 10 15 200
05
1
15
2
25x 10
-5
T (K)
The
rmal
diff
usiv
ity (
m2s
)
Thermal diffusivity
KaptonG10
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
31Susana Izquierdo Bermudez
Insulation MP
T [K]
(mW
mK
)
0
40
80
120
160
200
4 6 8 10 12 14 16 18 20
GM GMG GMHT CGMG CGM G10
Sample name Composition Heat treated at 675 CGM 12 layers micaglass no
GMG 6 layers micaglass-6 layers glass noGMHT 32 layers micaglass yesCGMG 8 cables micaglass-glass yesCGM 8 cables micaglass yes
12 layers micaglass NHT
6 layers micaglass-6 layers glass NHT
32 layers micaglass HT
8 cables micaglass-glass HT
8 cables micaglass HT
Thermal Conductivity of Micaglass Insulation for Impregnated Nb3Sn Windings in Accelerator Magnets
Andries den Ouden and Herman HJ ten KateApplied Superconductivity Centre University of Twente POB 217 7500 AE Enschede The Netherlands
32Susana Izquierdo Bermudez
QH
32Susana Izquierdo Bermudez
QH
