Simulation and measurement of pulse height and rise-time for electron signals in CZT detectors:: influence of material and electronics parameters

A model for simulation of amplitude vs. rise-time biparametric spectra as a function of CZT materials properties was developed. This model takes into account the physical properties of the CZT detectors, the electric field profile and the physics of γ- ray interaction with CZT. The model has been refined to include the filtering effects of the front-end electronics and applied again to biparametric spectra. The electronic filtering is represented by a combination of linear band pass filters. The rise-time measurement circuit induces a non-linearity that is taken into account. A comparison between the electronics simulations and calibration measurements on the actual circuits is presented. In addition, physical and electrical properties of several CZT samples have been characterized and these properties have been incorporated in the model so that actual and simulated biparametric spectra can be compared. Finally, the model is applied to show the influence of the main physical parameters (mobility and lifetime) and of the applied electric field on the biparametric spectra.