期刊
出版社
ELSEVIER
DOI: 10.1016/j.nima.2015.06.013
关键词
Gamma rays; Total mass attenuation coefficient; Optimum thickness; Mean free path; Scatter acceptance angle
Gamma ray shielding behaviour of any material can be studied by various interaction parameters such as total mass attenuation coefficient (pm); half value layer (HVL); tenth value layer (TVL); effective atomic number (Z(eff)), electron density (N-el), effective atomic weight (A(eff)) and buildup factor. For gamma rays, the accurate measurements of mu(m) (cm(2) g(-1)) theoretically require perfect narrow beam irradiation geometry. However, the practical geometries used for the experimental investigations deviate from perfect-narrowness thereby the multiple scattered photons cause systematic errors in the measured values of mu(m) Present investigation is an attempt to find the optimum value of absorber thickness (low-Z) for which these errors are insignificant and acceptable. Both experimental and theoretical calculations have been performed to investigate the effect of absorber's thickness on mu(m) of six low-Z (10 < Z(eff) < 14) construction materials (cement-black; cement-white; clay; red-mud; lime-stone and plaster of paris) at gamma-ray energies 661.66 key, 1173.24 key and 1332.50 keV. A computer program (GRIC2-toolkit) was designed for theoretical evaluation of shielding parameters of any material. Good agreement of theoretical and measured values of mu(m) was observed for all absorbers with thickness <= 0.5 mean free paths, thus considered it as optimum thickness for low-Z materials in the selected energy range. White cement was found to possess maximum shielding effectiveness for the selected gamma rays. (C) 2015 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据