Determination of mass attenuation coefficients for several natural minerals in Malaysia

Abstract

Mass attenuation coefficient (µm) is an important parameter in both fundamental and applied mineral studies. The purpose of this study is to determine the values of mass attenuation coefficients of several natural minerals from various mining areas in Malaysia. Four types of minerals were chosen which are hematite, tin ore, xenotime and monazite. The samples were prepared in pallet form by mixing 7g of each sample with 3g of wax. The dimension of the pallet was 3mm in thickness and 40 mm in diameter. The element compositions of the samples were determined by using X-ray fluorescence (XRF) spectroscopy. The gamma attenuation spectra were obtained by irradiating the sample in the energy range of 50-1500 keV with hyper pure germanium (HPGe) detector. The data were analyzed using Lambert-Beer’s law to obtain experimental mass attenuation coefficient values. The theoretical mass attenuation coefficients were calculated using WinXcom software based on the concentration of elements and oxides from XRF data. The result showed that for tin ore, the experimental mass attenuation coefficients fitted well to the theoretical value with the average values of 2.382, 1.840 and 0.095 g cm-3 for the energy range of 50-300, 300-1000 and 1000-1500 keV respectively. On the other hand, the results from other three types of samples showed a slight less consistency between experimental and theoretical values.