The Effect of a High Radiation Environment on Gold-Silicon Charged Particle Detectors

A study was conducted to determine the effect of a high radiation environment on the response of gold-silicon surface-barrier detectors to plutonium-239 alpha particles. The controlling damage was due to fast neutrons although the detectors were exposed to a mixed gamma-neutron field. After an exposure of 1000 rads the low energy side of the response peak showed a definite but broad secondary peak. With increasing dose the original peak broadened but retained its pulse height and the secondary peak dropped in pulse height and became very broad. The total number of counts remained constant, being shared between the two peaks. After 5000 rads exposure the original single peak response was no longer evident. Thermal annealing at 180 C for several hours yielded only slight recovery.