Peak-shape Fitting in Presence of Trapping Effects in High-Z Detectors

We studied a peak-shape function given by the convolution of a Gaussian term and a weighted sum of left-side exponential decay terms and we tested it on X- and gamma-ray spectra acquired by a CdTe detector. The interesting feature of the proposed function is that it well describes the combination of mutually independent variables: the Gaussian term featuring a symmetric probability-density function (e.g. electronic noise) and the tail terms modeling purely asymmetric ones (e.g. incomplete charge collection, trapping, etc.). Fitting results are in agreement with the expected carrier dynamics in presence of trapping and allow a more precise evaluation of noise, peak position and tailing effects.