Computer simulations of the behaviour of the partial charge collection model in thick HgI2 γ-detectors

Abstract

Abstract The partial charge collection model has been reported as the most suitable technique to form good-resolution spectra with thick HgI 2 γ-detectors. This method is based on measuring the charge signal induced by the drift of the free carriers generated in the interaction, while the electrons have not reached the positive electrode, instead of taking the total pulse height as a measure of the energy. A computer simulation of the whole process, from the interaction of the γ-ray with the detector to the electronic signal treatment, has been developed. With the help of this tool, several situations concerning thick HgI 2 detectors have been considered, analysing different practical implementations of the partial collection method. In particular, two approaches, one based on shaping at short times and the other using a flash pulse digitation, have been extensively discussed and compared.