Barrel Capacitors

1
Barrel Capacitors

• With socket and bent pin, forms capacitor
  assembly
• Duke supplies capacitors, Hampton assembles

2

• 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

3

• HV discharging tests Duke 2002
• 50 capacitors from each lot charged up _at_ 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

4

• 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

5

• 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

6

• All samples, plus assorted glue/tape samples,
  inside aluminum tube 19 mm o.d. x 250 mm long
  required to fit into reactor

7

• 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

8

• Results
• Mounted capacitors being kept at HV no problems
  so far
• Possible decrease in capacitance (lt 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