Radiation-induced insulator discharge pulses in the CRRES internal discharge monitor spacecraft samples

The internal discharge monitor (IDM) was designed to observe electrical pulses from common electrical insulators in space service. The 16 insulator samples include G10 circuit boards, FR4 and PTFE fiberglass circuit boards, wires with common insulations, FEP Teflon, and alumina. Pulsing characteristics differ among the sample materials. FEP differs significantly from TFE Teflon, and fiber-filled material differs from bulk material. The samples are fully enclosed and mutually isolated, and space radiation penetrates 0.2 mm of aluminum before striking the samples. No bias is applied; the electric fields are generated by trapped space charge due to the stopping of high-energy space electrons. The IDM results indicate the rate at which insulator pulses occur in space. The pulse rates are compared with space radiation intensities and energy spectra as measured by the CRRES (Chemical Release and Radiation Effects Satellite) satellite radiation detectors