A Zero-Crossing Pulse Shape Discriminator for Space Applications

A circuit for discriminating neutrons, gammas and charged particles from each other in a phoswich scintillator is described. The scintillator is intended for use as a fast neutron detector. Test results indicate that the particle discrimination capability, noise rejection, and pulse pile up rejection are good. The circuit is capable of operating with very little degradation over a wide temperature range. Energy information for neutrons and gammas is also simultaneously obtained. The dynamic range is at least 20:1. The circuit has the capability of accepting count rates up to 4 × 105 per second without loss of information.