HiLumi-LHC / LARP Conductor and Cable Internal ReviewOctober 16th and 17th 2013
H. Felice
LARP Short MagnetsFabrication and Test experience
relevant to QXF conductor and cable specifications
H. Felice 2
What is a successful magnet?
A magnet in which every single stage of fabrication has been successful
A magnet will be considered successful when I quench > 90 % Iss
10/17/2013
LARP history illustrates the involvement of each of these steps in magnet success and failures…
Cable Coil Fabrication Assembly - PreloadStrandDesign
H. Felice 3
Successful LARP Magnets
10/17/2013
Large parameter space covered by short models
H. Felice 4
From TQS02 series to TQS03 series
TQS02c •High RRR (>200)• 70 microns filament• 47 % Cu fraction• Jc (12T, 4.3 K) 2925 A/mm2
Tested at CERN
TQS03• High RRR (>200)• 50 microns filament• 54 % Cu fraction• Jc (12T, 4.3 K) 2770 A/mm2
Tested at CERN
205 – 210 T/m
220T/m
Moving from 54/61 to 108/127 improved performances at 1.9 KIn TQ
10/17/2013
220 T/m 238 T/m
H. Felice 5
TQS03 series and stress limit
-280-260-240-220-200-180-160-140-120-100
-80-60-40-20
0
Ti pole L1 pole L1 mp L2 pole L2 mp
Azi
mut
hal s
tres
s (M
Pa)
TQS03a
TQS03b
TQS03c
TQS03d
With Lorentz forces at 12 kA
10/17/2013
4 tests: TQS03 a, b, c and d
• performed with variable pre-stress• TQS03a: 120 MPa• TQS03b: 160 MPa• TQS03c : 200 Mpa• TQS03d: 120 MPa
After cool-down
-260-240-220-200-180-160-140-120-100
-80-60-40-20
0
Ti pole L1 pole L1 mp L2 pole L2 mp
Azim
utha
l str
ess (
MPa
)
TQS03a
TQS03b
TQS03c
TQS03d
H. Felice 6
TQS03 training
10/17/2013
TQS03 series demonstrated- Progressive degradation: but only 5 % from a to c- Permanent degradation beyond 200 MPa preload- QXF should have margin
• Magnet: pole turn (preload) / max midplane stress (excitation)• TQS03a: - 120 / -190 MPa• TQS03b: - 160 / -240 MPa• TQS03c : - 200 / -260 Mpa• TQS03d: - 120 / -190 Mpa
• Quench location:Midplane area
H. Felice 7
HQ series overview
HQ01 a-b-c-d-eMagnets with mixed coilsCoils 1-2-8-9 => 54/61Coils 3-4-5-6-7 => 108/127
Performance (LBNL and CERN)• 4 magnets => 70 to 85 % Iss at 4.4 K• HQ01e test at CERN => 85 % at 1.9
K
HQ02a and a2Same conductor in all coilsCoils 15-16-17-20 => 108/127
Performance (FNAL)• 98 % at 4.5 K• 89 % at 2.2 K
A. GodekeA. Godeke
10/17/2013
2 of each / magnet
H. Felice 8
HQ series performance overview
HQ01 series
HQ02
Reached 80% in 2 quenches
Good memory
What changed? • The coil fabrication
• Cable with Stainless steel core
HQM04
97% at 4.5 K
94% at 2.2 K
Maxim Marchevsky Guram Chladidze
10/17/2013
H. Felice 9
Impact of coil fabrication
Review of the coil fabrication process and designÞ High compaction of the winding during fabricationÞ Tooling and coil design oversight: no margin to allow for cable expansionÞ Risky end design
Suspected to be the cause of conductor degradation in potted coils
Main requirement for HQ02 coils: using the same tooling as HQ01•Accounting for dimensional changes and interlayer insulation
Smaller cable with smaller strand => 0.778 mm diameter strand => 14.8 mm x 1.375 mm
Axial gap size 4 mm/m•Revision of the end parts design
10/17/2013
Lead end
R, Hafalia, S, Caspi
H. Felice 10
HQ experience applied to QXFconductor
• Cable dimensional change accounted for in the magnetic design and tooling design
• 4.5 % in thickness and 2 % in width in ROXIE cross-section• Design made with reacted cable dimensions• Based on HQ and LQ experimental data
Importance to provide actual cable dimensional changes data for QXF cable to magnet designers
10/17/2013
H. Felice 11
Impact on coil fabrication schedule
Last HQ01 coil #9 completed end of 2010HQ01d and e tested starting April 2011
1st Mirror test at FNAL HQM01
2nd Mirror test at FNAL HQM02• 1 less turn• 91 % Iss at 4.6 K• 89 % Iss at 2.2 K
3rd Mirror test at FNAL HQM04• New end parts• New cable
HQ02 tested at FNAL
To validate compaction theory09/2011
05/2013
05/2012
04/2011
• Unforeseen change of cable in the case of HQ02 delayed strongly the magnet production
• QXF 2nd generation cable should be defined very early to facilitate implementation
10/17/2013
H. Felice 12
HQ Winding Experience
HQ01: 1st generation of coils• 2 pass cable• Mechanically stable
HQ02: 2nd generation of coils
• 1 pass cable to implement the stainless steel core• “Easy” popped strands noticed by technicians in some coils
• Easily fixable
HQ02 experience => Learning experience on how to handle less mechanically stable cables
10/17/2013
D. Dietderich - F. Borgnolutti
H. Felice 13
Impact of SS core in HQ performance
10/17/2013
X. Wang, J. DiMarco, M. Marchevsky – Guram Chladidze
HQ01 / HQ02 performance
• Beneficial effect on ramp rate dependence
• Beneficial effect on field quality
H. Felice 14
Summary
10/17/2013
• LARP short models performance widely influenced by all the production chain
• Best examples: HQ01 to HQM04 / HQ02• With coil fabrication improvement => performance improvement
• despite low RRR in coil 15
• What to remember from short model program for QXF
• Cable• Beneficial effect of the core cable on field quality and ramp rate dependence• let’s keep in mind the potential delay to implement a new cable design
• Coil fabrication / tooling design: • Data for Effective dimensional changes in the design
• Assembly: Stress level in conductor => TQS03 is a good guideline
