%0 Journal Article %T Gaussian Energy Broadening Function of an HPGe Detector in the Range of 40£¿keV to 1.46£¿MeV %A E. Eftekhari Zadeh %A S. A. H. Feghhi %A E. Bayat %A G. H. Roshani %J Journal of Experimental Physics %D 2014 %R 10.1155/2014/623683 %X High-purity germanium (HPGe) detectors are widely used in nuclear spectroscopy (e.g., neutron activation analysis) due to their high resolution. Resolution function of a GMX series coaxial detector system (model number GMX40P4-83) in the range of 40£¿keV to 1.46£¿MeV has been measured using standard ¦Ã-ray sources. The energy response function also was calculated using Monte Carlo simulation through the precise modeling of the detector structure. The simulated energy response function was verified with the measured energy response function obtained using calibration sources. A new approach was used and the agreement between both results has been improved. 1. Introduction The use of germanium detectors has completely revolutionized gamma spectroscopy. The great superiority of the germanium system in energy resolution allows the separation of many closely spaced gamma-ray energies, which remain unresolved in the NaI(Tl) spectrum [1]. Our final aim is to benchmark MCNPX code with experiment to be used in neutron activation analysis because creating a library to train a neural network to analyze the measured spectrum obtained from activated sample under irradiation of neutrons by experiment is irritating, cost-intensive, and time consuming. The Monte Carlo simulation can be used for this reason to generate this library making it easier and cheaper. In this case we need the exact response function of the HPGe which is needed to account for any possible noises that may have influence on FWHM in order to create a nearly real simulation. Resolution function of an HPGe detector can be determined with experimental measurements for the energy range of interest by using radioactive sources. Only few studies deal with the use of germanium detectors in both low- and middle-energy range of gamma-ray which is important in the field of activation analysis [2¨C4]. This work performed modeling of an HPGe detector for low-energy to middle-energy gamma-ray and its validation with experiment using standard gamma-ray sources. In addition , , and as parameters specifying the Full Width at Half Maximum in the GEB option have been extracted to make efficient Monte Carlo simulations of germanium detectors. 2. Material and Methods 2.1. Experimental Approach The detector used in this study was a GMX series HPGe coaxial detector system: the detector model number: GMX40P4-83; cryostat configuration: CFG-PG4-1.2; preamplifier model: A257N; HV filter model: 138 EMI. The resolution (FWHM) at 1.33£¿MeV, 60Co is 2.02£¿keV and peak-to-Compton ratio, 60Co is 59£¿:£¿1 and relative efficiency at %U http://www.hindawi.com/journals/jep/2014/623683/