Effect of finite absorber dimensions onγ-ray attenuation measurements

Using ${}_{}{}^{137}{}_{}{}^{}\mathrm{Cs}$ γ rays, the effect of finite absorber dimensions on attenuation measurements has been studied. Copper and mercury targets were used. Absorber dimensions up to five mean free paths were used. A correlated effect was observed in the measurements due to absorber thickness and its dimensions in the transverse directions. The values of the attenuation coefficients for copper and mercury have also been determined.