Statistical modeling of pulse height spectrum of gamma-ray spectrometers limited by incomplete charge collection

Abstract

This letter presents an analytic approach to the calculation of the pulse height spectrum, using a statistical model, which simultaneously considers a random point of photon absorption (i.e., nonuniform absorption) and a random drift time for each carrier. The pulse height spectrum of gamma-ray spectrometers is calculated as a function of photon energy, electron and hole mobility-lifetime products and applied electric field. For spectrometers with a uniform electric field the pulse height spectrum is obtained by a single numerical integration of an analytical expression.