Microplasmas in Silicon p-n Junctions as Detectors for Gamma Radiation

Abstract

A counting device of very small dimensions is described which may preferably be used as counter for γ radiation. When operating a silicon diode (alloyed type) in its prebreakdown region, where the breakdown is unstable and giving voltage pulses, the rate of these pulses is a linear function of the incident radiation. In that way the device shows a behavior like a Geiger-Müller tube with large breakdown pulses and small ``deadtime'' (several micro-seconds). Measurements were taken with a 350-C Co60 source in the range of 10 to 104 R/h. As an extrapolation indicates, the device may be used for dose rate measurements up to 107 R/h. Temperature and time stability of the effect are discussed.