ANALYSIS ON X AND γ-RAY ATTENUATION FOR EXTENDED SOURCES IN AIR

Abstract

As for attenuation of X and γ-ray intensity which varies with source distance, inverse squares law is applied. But it is not satisfied for actual case because of extended sources and absorption by air. Therefore intensity is shifted from inverse squares law, so we calculated shifting ratio from the law based on X and γ-ray spectra. As a result, the ratio varies with the size of the source and distance from it, and X-ray intensity in diagnosis, in case of standard value at 1 meter, is shifted within ±5%, ±8% for dose and fluence respectively.