Radiation shielding properties of some igneous rocks in isparta province at different gamma energies: Experimental and theoretical study

Abstract

In this study, our aim is to experimentally and theoretically obtain the gamma radiation shielding properties of some igneous rocks extracted in Isparta, Turkey. In the first stage, experimental measurements were performed using a gamma spectroscopy system containing a NaI(Tl) detector at three different gamma energies (511, 835 and 1275 keV) emitted from two different radioactive sources (22Na and 54Mn). As a result of the experiments, linear attenuation coefficients (LACs) of igneous rocks were obtained. The variation of LAC was investigated in relation to the density and the alkali-silica content of the rocks. The results obtained indicated an increase in the LACs with higher rock and an elevated alkali-silica ratio. Using the experimental LAC results, the half and tenth value layer thickness (HVL and TVL), mean free path (MFP), transmission rate, radiation protection efficiency (RPE) and lead equivalent thickness (dPb) values were calculated. In the second stage of this study, LACs were calculated theoretically with the help of XCOM software using the chemical contents of the selected igneous rocks. The comparison of experimentally obtained LACs with those calculated using the XCOM software, revealed a good agreement between the two methods. In addition, the results obtained with the XCOM software gave information about the variation of the attenuation coefficient in different energy regions. Moreover, effective atomic number (Zeff) and electron density (Ne) parameters were calculated using XCOM and experimental results. Based on the data collected, it can be concluded that the trachy-basalt sample taken from the igneous rocks used in this study is more effective than other rocks in terms of gamma radiation shielding.