High temperature behaviour and long-term stability of lithium drifted silicon surface-barrier detectors

Abstract Lithium-drifted silicon surface-barrier detectors have been fabricated which exhibit stable electrical and α-particle characteristics under conditions of prolonged aging and repeated exposure to thermal-vacuum environments. The detectors will operate at a temperature of 85°C abd high vacuum for several days and at a temperature of 100°C and high vacuum for several hours, with no evidence of noise instability. The operating characteristics of such detectors have been studied over a period of fourteen months. These studies included measurements of their electrical and α-particle characteristics taken before, during and after extended thermal-vacuum testing at 50°C and 85°C and short-term testing at 100°C. Degradation in electrical and α-particle characteristics resulting from such testing and aging was found to be negligible over the fourteen month time period. The α-particle measurements at 100°C indicate that the fractional change in the mean energy per ion pair in going from room temperature to 100°C is approximately −1.8%. The results of these studies are reported.