A Gain Stabilised Semi-Conductor Compton Spectrometer

A semi-conductor gamma-spectrometer system is presented in which gamma-rays scattered out of the primary detector by Compton events are registered in a NaI crystal and give rise to a coincidence pulse which gates the input to the multichannel analyser. A simple single interaction model for calculating the efficiency of such a spectrometer is suggested. A comparison of the efficiency computed from the model and from the experimental.measurements is made and shows that within the precision of the model the agreement achieved is adequate. The short term gain stability of the spectrometer using a spectrum stabiliser and reference gamma source is investigated. (author)