A DEDICATED EMPIRICAL-FORMULA FOR GAMMA-RAY BUILDUP FACTORS FOR A POINT ISOTROPIC SOURCE IN STRATIFIED SHIELDS

A dedicated empirical formula for evaluating gamma-ray buildup factors of double-layered shields for a point isotropic source has been propo sed for the first time by fitting it to the data of Monte Carlo calcul ations using EGS4 code. The calculated results from the present formul a were compared with those using other empirical formulae. The extensi on of the present formula in the application for multilayered shields was tested for a number of combinations of stratified shields. By usin g infinite-medium buildup factors of single materials, the present for mula will deliver buildup factors of stratified shields without suffer ing boundary effect instead of the ones of transmission type. Copyrigh t (C) 1996 Elsevier Science Ltd