Ar. Frederickson et al., Gaseous discharge plasmas produced by high-energy electron-irradiated insulators for spacecraft, IEEE PLAS S, 28(6), 2000, pp. 2037-2047
High-energy electron irradiation of insulators in vacuum causes both intern
al regions and surfaces of insulators to achieve high (negative) static vol
tage relative to nearby "ground," Occasional spontaneous discharges inject
pulses of partially ionized gas composed of the insulating material and sur
face gas-adatoms into the adjacent vacuum. The gas is capable of partially
discharging the high surface potentials by carrying current across the vacu
um to ''ground." The current-time waveforms were measured as a function of
the spatial arrangement of the sample, test chamber electrodes, and static
electric fields in order to investigate effects inside spacecraft boxes and
cavities, It was found that plane-parallel electric fields are less able t
o sustain large discharge currents than are divergent electric fields. Also
, physical confinement of the pulse of gas within the region of the electri
c held greatly increases the conductance of the gaseous discharge. Thus, th
e spatial arrangement of the sample, test chamber electrodes, and static el
ectric field has a strong impact on the level of ESD-pulse threat to sensit
ive electronics posed by spontaneous discharges of irradiated insulators in
spacecraft.