Study the effect of samples chemical composition on the quality of gamma measurements using Mont-Carlo simulation

Wafaa F. Bakr

Performing accurate relative measurements of sample’s activities using a Hyper Pure Germanium detector (HPGe) necessitates the use of calibration standards. However, standards with similar characteristics like those of the measured samples are not usually available. This work aimed at studying the effect of variation in chemical compositions of measured samples on the accuracy of the gamma analysis used hyper purity germanium (HPGe) detector-based spectrometers. The Monte Carlo simulation technique is used to obtain the detector response due to four different standard soil samples. The samples were assumed to be identical except for chemical compositions and slight variations in densities. The simulation process involves the modeling of a HPGe detector for which the pulse height tally “F8” is calculated at different common gamma ray energy lines using the MCNP5 Code for the four samples. The analysis covered gamma energies ranged from 46.5 up to 1764.0 keV. The results showed that the effect of soil's chemical compositions is less than 0.5% for gamma energy greater than 186.2.0 keV.

https://dx.doi.org/10.31873/IJEAS.6.1.13