seog oh/ duke university/oct, 2002 trt/ atlas week at cern hv capacitor testing
TRANSCRIPT
Seog Oh/ Duke University/Oct, 2002 TRT/ ATLAS week at CERN
HV capacitor Testing
Seog Oh/ Duke University/Oct, 2002 TRT/ ATLAS week at CERN
Two tasks Capacitor testing (Duke) Capacitor preparation (Hampton)
Capacitors under testing Johanson surface mount 1000pf, rated 2000 V, size 821. Material : X7R
Choices are limited due to space Capacitors from four different lots (batches). ~Two years ago, the same capacitors (from different
lots) were radiation tested at CERN and the results were mixed.
Seog Oh/ Duke University/Oct, 2002 TRT/ ATLAS week at CERN
HV testing HV cycle
Connect 30 capacitors from each batch to HV=2000 V and discharge.
Measure the total capacitance every 50 discharges. Number of cycles : 2000
Results Batch 1
One capacitor– Surface HV breakdown during 1500-1550 cycles
– Inner HV breakdown during 1600-1650 cycles Batch 2/3/4 : No problem
Conclusion : Pass
Seog Oh/ Duke University/Oct, 2002 TRT/ ATLAS week at CERN
Test setup
Seog Oh/ Duke University/Oct, 2002 TRT/ ATLAS week at CERN
HV Test
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Trial/50
To
tal C
apac
itan
ce (
nf)
Seog Oh/ Duke University/Oct, 2002 TRT/ ATLAS week at CERN
Plan Repeat the same test with capacitors from HU
(encapsulated and legs are attached) Long term test
30 capacitors from each batch connected to HV=2000 V and current is monitored.
Irradiation test – CERN Requirement : All capacitors from all batches should pass.
Decision by the end of 2002. There should be no problem in getting the capacitors (~6 weeks).
Radiation test on ~100 random samples once the production batch is available
Option in case of failure Go to lesser capacitance with different material (NPO)