Effects of Gamma Irradiation on Soil Samples

Linear and mass attenuation coefficients are widely used in the study of gamma rays, calculation of photon penetration and energy deposition in biological shielding, in industry, agriculture and other materials. There are various reports on the measurements of these quantities by scientists.

Singh et.al (1991) measured energy absorption coefficients for gamma rays in different soil samples by applying Bradley et. al .(1989) technique. Jahagirdar (1992) determined narrow beam attenuation coefficients of 320 keV photons, emitted from 51Cl radioisotope in various high Z materials such as (CH3COO)2.Pb.3H2O; Pb(NO3); Na2WO4.2H2O by using NaI (Tl) spectrometer system coupled to 1 k multichannel analyzer and results are compared with tabulations of Hubbel (1992). The self absorption factors were determined by Yu Cagin et.al.(1990).

So far, evaluation of both types of coefficient (attenuation and energy absorption) for gamma rays has been performed for materials in solid and crystal forms. Mixture rule for theoretical calculation of absorption coefficients developed for elements by Hubbell (1982).

Dr. M.T. Teli and Dr. L. M. Chaudhari (1994) developed mixture rule for liquid and studied the linear absorption coefficient of various gamma radiation by dilute solutions of various salts such as sodium chloride, potassium chloride, ammonium chloride and aluminium chloride, etc. at various concentrations by using gamma energies.

In view of the importance of the study of gamma attenuation properties of materials and its various applications in science, technology, agriculture and human health, we have embarked on study of the absorption properties of soil samples containing various Chemical and Physical properties composed of various elements.

By using the previous techniques, we explore the validity of the expected exponential absorption law for gamma radiation in soil samples collected from different areas of Nanded, Latur, Osmanabad District from Maharashtra and Bidar District from Karnataka of India. We also studied the behavior of soil density with gamma attenuation coefficient at various energies.