Gamma Ray Buildup Factor Studies in Composite Materials

The work presented in this thesis deals with study of; (i) buildup factors in composite materials like HCO-materials (materials containing H, C and 0 as constituents), soils, water, air and concrete, and (ii) the phenomenon of multiple scattering of gamma rays in different soils. From shielding point of view the two parameters which are of interest to scientific Community, are the set of attenuation coefficients and the buildup factors of the given materials for a wide energy range and penetration depth. In literature attenuation coefficients data in a variety of compounds and elements is available. But the buildup factor data is available only for a few elements and for water, air and concrete. Typically build up factor may be defined as a multiplicative factor to get the corrected response to un-collided photons by including the contribution of scattered photons. Its use is now well established in practical calculations of gamma ray attenuation process. Soil could serve as a potential shielding material in field conditions and the HCO-materials are widely used in nuclear industry in one form or the other, hence the need to have buildup factor data for these materials.