Study of some factors affecting the measurement of gamma rays Buildup factor in aluminum and lead materials

Abstract

In this research Buildup factor of gamma rays in the lead and aluminum substances using the Geiger tube detector and the Cobalt-60 radioactive source.For a distance of (60mm) between the cobalt-60 radioactive source and detector, the effect of atomic number variation and thickness of the shield material in units (mm) and mean free path units (m.f.p) on the Buildup factor values had been studied, and the effect of changing of the distance between the cobalt-60 radioactive source and detector on the Buildup factor had been studied for constant thickness value (10mm) of aluminum material shield.Also the effect of changing of collimator hole diameter and gamma rays energy had been studied for distance (60mm) between the radioactive source and the detector using cesium-137 and cobalt-60.This study provide that Buildup factor of gamma rays increases with decreasing of the atomic number of shield material and with increasing of the shield thicknesses, and it decreases with increasing of distance between the radioactive source and detector and with increasing collimator hole diameter, as well as it decreases with increasing of gamma rays energy or radioactive source energy.