Abstract

In this paper the MCNP code was used for the simulation of complex gamma spectra measured in the GC1518 HPGe detector at the Center for Nuclear Techniques Ho Chi Minh City. The calculation was performed using the thickness of 1.16 ± 007 mm of inactive germanium layer obtained our previous paper. The better agreement between calculation and experiment results was obtained for three radioactive sources 131I, 238U and 232Th when the inactive germanium thickness was changed from 0.35 mm into 1.16 mm. Indeed, in the case of d = 0.35 mm the ratios of the calculated and measured photopeak areas are greater than unity in the energy range of below 200 keV and approximately unity in the energy range of above 200 keV. Meanwhile, in the case of d = 1.16 mm these ratios are approximately unity in the whole energy range of 63.3 ke V to 1847.3 keV.