Post on 06-Jan-2018
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ATLAS TRTDuke University CERN, Feb. 2003
Barrel Capacitors
With socket and bent pin, forms capacitor assembly Duke supplies capacitors, Hampton assembles
ATLAS TRTDuke University CERN, Feb. 2003
Baseline: Johanson 202S43W102KV4E:
202: 2000V S43: size 1812 = 4.45 x 3.18 x 2.16 mm W: X7R dielectric – but NP0 now available 102: 1,000 pF K: tolerance ±10% V: nickel barrier termination 4: no marking E: 7 inch embossed reel (1000 pieces)
Four reels from different lots purchased for tests
ATLAS TRTDuke University CERN, Feb. 2003
HV discharging tests – Duke 2002: 50 capacitors from each lot charged up @ 2000V
then shorted – repeat 3000 times Measure capacitance, current leakage, arcing Results:
a few failures on surface (dirt?) Average capacitance decreases by a few %
Conclusion: capacitors pass test
ATLAS TRTDuke University CERN, Feb. 2003
Radiation Hardness Test – Duke/N.C. State 2003 PULSTAR reactor:
1 MW pool-type; 4% enriched pin-type fuel consisting of uranium dioxide pellets in zircaloy cladding
ATLAS TRTDuke University CERN, Feb. 2003
Samples for exposure: For each lot: (four lots)
10 capacitors soldered in parallel on board – will be at HV during test
10 capacitors left in reel packaging
ATLAS TRTDuke University CERN, Feb. 2003
All samples, plus assorted glue/tape samples, inside aluminum tube – 19 mm o.d. x 250 mm long – required to fit into reactor
ATLAS TRTDuke University CERN, Feb. 2003
Radiation: 60 minutes of 30% reactor power Fast and slow neutrons
Total n fluence measured with Co foils – varied from 1.2 to 9 x 1014 / cm2 (top to bottom)
~ 50 years LHC operation Gammas
~ 2 Mrad 40 capacitors at 2000 V:
Leakage current: .4 μA before / after irradiation .8 μA during
ATLAS TRTDuke University CERN, Feb. 2003
Results: Mounted capacitors being kept at HV – no
problems so far Possible decrease in capacitance (< 3%) Plan to do discharge test on unmounted ones –
when they cool off Will look for “Anatoli Desk Effect” Plan to test NP0 version Plan to test full assemblies from Hampton
Conclusion: baseline capacitors OK