MCNP5 modelling of HPGe detectors for efficiency evaluation in gamma-ray spectrometry

Abstract

A modelling of HPGe detectors was performed through simulation with the MCNP5 Monte Carlo code. The simulation results concerning the values of the main physical parameters of the detector are in most cases different from those provided by the manufacturer. The use of “single-line” sources allows us to suitably modify the parameter values used in the detector model. For a detector model, the simulation assesses the distribution of photopeak and total efficiency for point sources, whereas for extended sources a control volume approach allows us to determine elementary efficiency behaviours. An integration of elementary efficiencies over the entire sample volume allows us to evaluate global efficiency.