HPGe Detector Energy Response Function Calculation Up to 400 keV Based on Monte Carlo Code

Abstract

A high purity germanium detector (HPGe) of crystal size of diameter 4.91 cm and length of 3.6 cm  was modeled in accordance with the Pop Top cryostat configuration (model no. GEM10P4). The energy response function was calculated in the air using Monte Carlo simulation with mono-energy g-ray photon up to 400 keV. The distance between the source and the front surface or end cap to detector was 20 cm and the source was assumed as an isotopic point source. The aluminum absorbing layers of thickness 0.127 cm was also taken into consideration in the simulation model. The input number of particles was 107 for each mono-energetic g-ray photon. The simulated energy response functions were verified with the measured energy response functions obtained using calibration sources in order to prove the accuracy of the modeling. The comparison between the measured energy response functions and the simulated energy response functions after normalization were also performed.  Keywords: HPGe; Gamma-ray spectrum; Monte Carlo. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i3.4668                 J. Sci. Res. 2 (3), 479-483 (2010)