A novel method to estimate the dead layer of HPGe detector for Monte Carlo FEPE computation

Abstract

In this study, a novel method to determine the surface and lateral dead layers of p-type HPGe detector is proposed to compute the full energy peak efficiency (FEPE). The method employed standard radioactive point sources 241Am, 133Ba and FEPE measurement at low energies to estimate the thickness of frontal and lateral dead layers. The method is simple to apply, requires only two standard radioactive sources to estimate the optimum thickness of frontal and lateral dead layers. The proposed method is validated by measuring the efficiency of various point sources and a volume source in the energy range from 59 to 1408 keV. The measured efficiencies agree to simulation with relative deviation less than 4.0% at each energy. The proposed detector model enables to calibrate the detector for environmental radioactivity measurement without standard volume sources.