Post on 26-Jul-2021
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General layout of the barrel detectorGeneral layout of the barrel detector
RB4 … … 120 chambers
RB3 … … 120 chambers
RB2 … … 120 chambers
RB1 … … 120 chambers
One barrel sector … … … … … ......60 sectors
General layout of the forward detectorGeneral layout of the forward detector
RPC in avalanches… a simple model RPC in avalanches… a simple model
s
d
qs
+
-
-
n 0ve
qe
Qe < qe >= kηd
< Qe (d)> = qeln0
kηd
λη+ λ
eηd
- k= (εr d/s)/( εr d/s +2) - qel is the electron charge- no is the average size of the primary cluster- λ is the cluster density in the gas mixture- εr is the relative dielectric constant- d is the gap width- s is the electrode thickness
- k= (εr d/s)/( εr d/s +2) - qel is the electron charge- no is the average size of the primary cluster- λ is the cluster density in the gas mixture- εr is the relative dielectric constant- d is the gap width- s is the electrode thickness
SimulationSimulation
M avalanche fluctuation
Double gap conceptDouble gap concept
The double gap detector is made out by two single gaps. Between them a planeof readout strips is located.
The double gap detector is made out by two single gaps. Between them a planeof readout strips is located.
A foil of Cupper is draped around the sandwich. It ensure the reference for the signal transmission along the strip and it is the ground of high voltage ad low voltage
A foil of Cupper is draped around the sandwich. It ensure the reference for the signal transmission along the strip and it is the ground of high voltage ad low voltage
CU
-9 kV
Double gap CMS chamberDouble gap CMS chamber
A barrel chamber is made with 4 gapsA barrel chamber is made with 4 gaps
Termination resistors
Cupper foil(ground) wrappedaround the gaps
Z axisConnection to FE
G. Iaselli
- HV
- HV
- HV
- HV
a) b)
The double gap designThe double gap design
Double gap geometryimproves the efficiency andallows safer operation athigher threshold. Also thetime resolution improves.
Double gap geometryimproves the efficiency andallows safer operation athigher threshold. Also thetime resolution improves.
Basic parameters Bakelite thickness 2 mmBakelite bulk resistivity 1-2 .1010 Ω cmGap width 2 mmGas mixtures 95% C2H2F4,5% i-C2H10
Operating High Voltage 8.5 - 9.0 kV
# Gaps 2
Basic parameters Bakelite thickness 2 mmBakelite bulk resistivity 1-2 .1010 Ω cmGap width 2 mmGas mixtures 95% C2H2F4,5% i-C2H10
Operating High Voltage 8.5 - 9.0 kV
# Gaps 2
Basic parametersBasic parameters
Basic parametersBakelite thickness 2 mmBakelite bulk resistivity 2-3 .1010 Ω cmGap width 2 mmGas mixtures 97% C2H2F4, 3% i-C2H10
Operating High Voltage 8.5 - 9.0 kV# Gaps 2
Basic parametersBakelite thickness 2 mmBakelite bulk resistivity 2-3 .1010 Ω cmGap width 2 mmGas mixtures 97% C2H2F4, 3% i-C2H10
Operating High Voltage 8.5 - 9.0 kV# Gaps 2
In most part of the In most part of the muon muon system the value of the dose system the value of the doseintegrated in 10-years is below 1 integrated in 10-years is below 1 GyGy..
A large double gap RPC (A large double gap RPC (ρ =2 10 ρ =2 10 1111) has been irradiated with 11) has been irradiated with 11 mCi mCi of ofγ γ source ( source ( 6060Co ). The performance has been monitored continuously toCo ). The performance has been monitored continuously tospot possibly aging effects.spot possibly aging effects.
Absorbed dose 1.6Gy
Irradiation testsIrradiation tests
Currents and rateCurrents and RateCurrents and Rate
Currents and single rates measured by the chamber under irradiation with sourceCurrents and single rates measured by the chamber under irradiation with sourceopen and closed. The applied voltages have been corrected for pressure andopen and closed. The applied voltages have been corrected for pressure andtemperaturetemperature..
Efficiency and cluster sizeEfficiency and Cluster sizeEfficiency and Cluster size
Efficiencies of the chamber underEfficiencies of the chamber underirradiation with source open andirradiation with source open andclosed.closed.
Average number of fired stripsAverage number of fired stripsclosed to the one associated to theclosed to the one associated to theextrapolated trackextrapolated track..
BARI Gamma Irradiation FacilityThe Gamma Irradiation Facility
at X5 (CERN)The Gamma Irradiation Facility
at X5 (CERN)
155 cm
γ
Beamµ
RPC
20 Ci 137Cs source
Absorbed dose duringthe test: ~23 Gy
Total charge accumulated 525 C
Total charge accumulated 525 C
Total irradiation time 7x 106 s
Total irradiation time 7x 106 s
Irradiation tests are continuing at GIF with a lowresistivity chamber (ρ =2 10 10)
Irradiation tests are continuing at GIF with a lowresistivity chamber ((ρ =2 10 ρ =2 10 1010))
R&D BarrelR&D Barrel
• A full size RB2 chamber tested at GIF during summer-autumn 1999
• Results are very satisfactory
• A full size RB2 chamber tested at GIF during summer-autumn 1999
• Results are very satisfactory
Single gap mode
ρ=1011
R&D ForwardR&D Forward
Extensive R&D during 1999
• A full scale RE2/2 chamber built in Korea was tested at GIF
• A small prototype built in China was also tested at GIF
Extensive R&D during 1999
• A full scale RE2/2 chamber built in Korea was tested at GIF
• A small prototype built in China was also tested at GIF
RE2/2
)R(R
offon
γNSHV
−=
Sensitivity at Bari irradiation facilitySensitivity at Bari irradiation facility
1 double gap RPC (ρ = 2 • 1011Ωcm) 1.3 x 1.2 m2
Gas mixture: 95% C2H2F4 and 5% i-C4H10
No sensible variation withirradiation time is observed
15 mCi of 60Co
φγ ≈ 10 4 cm-2 s -1
Sensitivity for a RB1 CMSSensitivity for a RB1 CMS
RPC area20 x 20 cm2
RPC area250 x 250 cm2
I gap 0.9 10-2 1.21 10-2
II gap 0.79 10-2 1.16 10-2
Double gap 1.51 10-2 2.12 10-2
The RPC hit rate in the CMS RB1 to γ will be about 5 Hz/cm2
CMS Muon Barrel (RB1) γ spectrum into the RPCs gaps
thisLHC like test beam (this week)LHC like test beam (this week)
Production and control of Bakelite Production and control of Bakelite
Resistivity range :• 2/3 of production in the range ρ20 = 2-5 1010 Ω cm• 100% of production in the range ρ20 = 1-6 1010 Ω cm
Roughness range :• Ra ≤ 0.2 µm
Resistivity range :• 2/3 of production in the range ρ20 = 2-5 1010 Ω cm• 100% of production in the range ρ20 = 1-6 1010 Ω cm
Roughness range :• Ra ≤ 0.2 µm
Totals for barrel≈ 4000 Slabs ≈14000 m2
Totals for barrel≈ 4000 Slabs ≈14000 m2
These are the first 400 slabsThese are the first 400 slabs
A wrapping machine allows to have a protecting film on each face of the slab
A wrapping machine allows to have a protecting film on each face of the slab
The table to measure the resistiviryThe table to measure the resistiviry
First results from the mass productionFirst results from the mass production
CMS MEASURED
21,4%
1,2%
27,2%24,1%
9,2% 10,1%6,7%
0%5%
10%15%20%25%30%
BLACK
WHITE
YELL
OW RED
GREENBLU
E
BLACK
RESISTIVITY COLOR CODE[5 – 6.3]BLUE
[4 – 5 [GREEN
[3 – 4 [RED
[2 – 3[YELLOW
[0.95 – 2[WHITE
< 0.95 or >6.3BLACK
RANGE
(x 1010 Ω cm)COLOR CODE
400 slabs
Bakelite AgeingBakelite Ageing
Gamma (137Cs) Irradiation Facility
Gamma (137Cs) Irradiation Facility
(Α) ρ vs Temp. (0 C)(B) ρ vs Time (days)(C) Temp. vs Time
ρ no Temp. corrected
A
B
C
Source ON
Source OFF
Melaminic sample
The ASIC DesignThe ASIC Design
Technology: 0.8 µm BiCMOS ofAMS8 channelsPower supplies: +5 V; GNDPower consumption: ~ 45mW/channel
Technology: 0.8 µm BiCMOS ofAMS8 channelsPower supplies: +5 V; GNDPower consumption: ~ 45mW/channel
In
Vtest Preamplifier
Dummy Preamplifier
Gain stage
Vbias Vth Vdrive
Zero-crossingDiscriminator
Outp
OutmDriver
Vmon
Monostable
Improvements:Input impedance = 15 ΩBetter threshold uniformityImproved timingperformance
Improvements:Input impedance = 15 ΩBetter threshold uniformityImproved timingperformance
Discriminator Response in the dynamic rangeDiscriminator Response in the dynamic range
∆T ~ 10 ns
One-Shot response
Zero-crossing Discriminator response
∆T < 1 ns
Zero-Crossing Discriminator response
∆ t < 1 ns
Qth = 20 fC 1 fC < Qov < 20 pC
Test Results (14 prototypes)Test Results (14 prototypes)
In-chip delaydispersion
Typical timing response
Qth = 30 fC
0
1
2
3
4
5
6
1 10 100 1000 10000Qov (fC)
|Tm
ax -
Tmin
| (ns
)
Chip 1 Chip 2 Chip 3 Chip 4 Chip 5Chip 6 Chip 7 Chip 8 Chip 9 Chip 10Chip 11 Chip 12 Chip 13 Chip 14
23
23.5
24
24.5
25
25.5
26
26.5
1 10 100 1000 10000Qov (fC)
<Tim
e (n
s)>
[Arb
itrar
y ze
ro] Chip 1
Chip 2Chip 3Chip 4
VLSI selection and FE board testVLSI selection and FE board test
The VLSI will be grouped by:
•Threshold value at a fixed Vgain•Signal propagation delay and time spread among the 8 channels
The VLSI will be grouped by:
•Threshold value at a fixed Vgain•Signal propagation delay and time spread among the 8 channels
FE board tests:
•Measure of Vpower and Vref•Check of DAC dynamics range•Gains equalization•Width adjustment of the one-shot output•Height adjustment of the output pulse•Electronic check of the “test-branch” and of the “reading-branch”•Delay time measure•Burn in
FE board tests:
•Measure of Vpower and Vref•Check of DAC dynamics range•Gains equalization•Width adjustment of the one-shot output•Height adjustment of the output pulse•Electronic check of the “test-branch” and of the “reading-branch”•Delay time measure•Burn in
Gamma irradiation Gamma irradiation
Triga Mark II 250 kW Reactor in PAVIA
Neutron spectrum afterthe boral window
Neutron spectrum afterthe boral window
Simulation
NeutronEnergy
Φn
(n/cm2 sec)Total
(n/cm2 sec)
En < 0.4 eV 1.6 x 10 3
0.4 eV<En<10 KeV 3.4 x 10 5
10 KeV<En<10 MeV 2.5 x 10 55.9 x 10 5
The FE boards were put in the Thermal Column of the Reactor justin front of a boral window (to deplete thermal component)
The FE boards were put in the Thermal Column of the Reactor justin front of a boral window (to deplete thermal component)
Average CHIP SEU RATE
0,012
0,015
0,018
0,021
0,024
0 5 10 15 20
Fast Neutron Fluence ( x 1010 cm-2)
Ave
rage
CH
IP R
ATE
(Hz)
Assuming6 x 105 cm-2 s-1
Assuming6 x 105 cm-2 s-1
PRELIMINARY
PRELIMINARY
Each OR of 8 channels ( 1 chip) was counted (with open input )at Reactor ON and OFF to measure spurious neutron inducedevents (Single Event Upset)
Each OR of 8 channels ( 1 chip) was counted (with open input )at Reactor ON and OFF to measure spurious neutron inducedevents (Single Event Upset)
UCL Neutron Facilities at Louvain
Wide spectrum neutron source:
* beam from variable shaping collimator
* maximum irradiation area 25x25 cm 2 @ 2m from target
* protons on Be target @ 15µA maximum current
* yield of 15µA of 65 MeV protons at 2m: 3.6x10 7 n/cm 2 /s
* flat spectrum up to proton energy (65MeV maximum)
8 hours beam on the 27 June
UCL Neutron Facilities at Louvain
Wide spectrum neutron source:
* beam from variable shaping collimator
* maximum irradiation area 25x25 cm 2 @ 2m from target
* protons on Be target @ 15µA maximum current
* yield of 15µA of 65 MeV protons at 2m: 3.6x10 7 n/cm 2 /s
* flat spectrum up to proton energy (65MeV maximum)
8 hours beam on the 27 June
Neutron irradiationNeutron irradiation
Front-End electronicsSchedule
Front-End electronicsSchedule
• VLSI pre-production (1000 pieces): done
• Test of pre-production June 2000
• Neutron irradiation tests at Louvain June 2000
• Start tender of VLSI July 2000
• Start tender of FE boards September 2000
• VLSI pre-production (1000 pieces): done
• Test of pre-production June 2000
• Neutron irradiation tests at Louvain June 2000
• Start tender of VLSI July 2000
• Start tender of FE boards September 2000
Production OverviewProduction Overview
Barrel• Single gaps from industry
• RB1 assembled in China
• RB2 assembled in Italy
• RB3 assembled in Bulgaria
• RB4 assembled in Italy
Problems
Bulgarian funds not fully established
Barrel• Single gaps from industry
• RB1 assembled in China
• RB2 assembled in Italy
• RB3 assembled in Bulgaria
• RB4 assembled in Italy
Problems
Bulgarian funds not fully established
Forward• Single gaps from Korea
• RE1 assembled in China
• RE n/1 assembled in Korea
• RB n/2 assembled in Pakistan
• RB n/3 assembled in Pakistan
Problems
Still missing money (.7 -1.0 KCHF)
Forward• Single gaps from Korea
• RE1 assembled in China
• RE n/1 assembled in Korea
• RB n/2 assembled in Pakistan
• RB n/3 assembled in Pakistan
Problems
Still missing money (.7 -1.0 KCHF)
Resistive Plate ChambersBarrel
Resistive Plate ChambersBarrel
• Production of Bakelite already started (10% in February)
• Tender for single gap completed
• Front-end VLSI pre-production completed (1000 chips)
• Test towers under construction in Bari
• The first RB2 chamber ready by June
• Final front-end board ready
• Front-end irradiation test under way
• Tenders for VLSI and FE board in July
• Production of Bakelite already started (10% in February)
• Tender for single gap completed
• Front-end VLSI pre-production completed (1000 chips)
• Test towers under construction in Bari
• The first RB2 chamber ready by June
• Final front-end board ready
• Front-end irradiation test under way
• Tenders for VLSI and FE board in JulyTest towers
Assembly table
Resistive Plate ChambersForward
Resistive Plate ChambersForward
Definition of the single gaps design done
Definition of the mechanics and the assembly procedure May
Construction of single gaps in Korea June
Assembly of a forward sector in Korea and Pakistan July
Definition of the single gaps design done
Definition of the mechanics and the assembly procedure May
Construction of single gaps in Korea June
Assembly of a forward sector in Korea and Pakistan July
The forward single gap will be built in Korea using Italian bakeliteThe chambers will be assembled in China, Korea, Pakistan
The forward single gap will be built in Korea using Italian bakeliteThe chambers will be assembled in China, Korea, Pakistan
Production scheduleProduction schedule
Barrel:• Follow Dt production schedule• One wheel by middle of 2001• Few chambers by the end of the year
•Forward:• Design frozen by te end of the year
Barrel:• Follow Dt production schedule• One wheel by middle of 2001• Few chambers by the end of the year
•Forward:• Design frozen by te end of the year