Rad hardness tests Sept' 2003

1

• Rad hardness tests Sept. 2003
• Capacitor assemblies
• Thermal glue
• (optional) capacitor barrel sealant
• Two separate samples
• At Georgia Tech Co60 source, 20 Mrad
• At N.C. State reactor, 50 years LHC

2

• Production Capacitors
• Novacap 1808N821K202NX
• 1808 smaller than previous Johanson 1812
• Nominal 820 pF, actual 875
• 8000 assemblies already produced, uncoated
• 15 in each radiation sample
• 5 with HV experience
• 10 fresh, coated with Loctite Hysol PC18M
• Results
• No observed effect of radiation
• 10 nA _at_ 2750 V for 10 assemblies fixture

3

• Thermal Glue
• CHO-THERM 1641, mostly Al2O3
• Thermal conductivity 0.9 W/m-K
• Looking for radiation induced
• Change in thermal conductivity
• Loss of adhesion

4

• Results
• Both types of irradiated samples slightly yellow
• No loss of adhesion to FR4, aluminum, DTMROC,
  with or without primer
• Thermal conductivities (preliminary, thick
  samples not properly cured
• Co60 lt10 decrease in thermal conductivity
• reactor not yet measured

5

• Capacitor barrel sealants
• Hopefully wont be needed
• 3 silicone RTVs
• GE RTV11 2 part, viscosity 11000
• GE RTV160 1 part, viscosity 38000
• GE RTV615 2 part, viscosity 4000
• Samples filled ULTEM capacitor barrels

6

• Results
• No effect from either irradiation
• RTV11 sticks well, but is removable, with or
  without primer
• RTV160 bonds to ULTEM
• RTV615 very runny, slow curing, removable