Measurement of moisture content and gamma radiation shielding characteristics of tree species grown in Punjab

The present study deals with investigation of the moisture content and radiation shielding characteristics of 10 native and exotic tree species grown in Punjab State by using gamma scintillation detection method at oven dry state. The intensity of the emergent radiation was measured, when each of these tree species at a given moisture level was placed between a scintillation detector and a gamma source (¹³⁷Cs of energy 0.662 MeV and having strength of 1.0 microcurie). The obtained results show an appreciable evidence of radiation attenuation due to the variable chemical composition of the selected tree species and the dependence of the attenuation coefficient on density. The obtained mass attenuation coefficients at different moisture levels were plotted against the relative moisture content of tree species and it was observed that attenuation coefficient increases with decreasing moisture content, i.e., mass attenuation coefficient is least for completely wet sample and is highest for the oven dried sample. The obtained mass attenuation coefficient for selected trees of teak, babul, mango, shisham, chir pine, mulberry, oak, dek, safeda and poplar are in unit of cm²/kg: 128.5±9.3, 114.6 ± 4.2, 107.8 ± 6.4, 81.2 ± 8.2, 79.3 ± 5.9, 77.5 ± 8.8, 74.8 ± 6.5, 69.4 ± 9.2, 64.9 ± 7.0 and 64.1 ± 8.2, respectively.