MONTE CARLO SIMULATION OF THE RESPONSE OF Si(Li) X-RAY DETECTORS TO PROTON INDUCED K X-RAYS OF LIGHT ELEMENTS

Abstract
A new detector model is deduced from measured ratios of low energy background counts to photopeak counts. This detector model assumes both the existence of a surface layer with reduced charge carrier collection efficiency and the existence of a low concentration of small regions of detector defects which have enhanced charge carrier recombination probability within the volume of the Si(Li) detector. Monte Carlo simulations of the response of two different Si(Li) detectors to K X-rays have been performed in order to quantify possible contributions of detector front contact and dead layer, respectively, to the measured X-ray spectra. Upper limits of those contributions and upper limits of dead layer thickness are given. The consequence of these results for detector efficiency calibration measurements are discussed.