Measurement of ¹³⁷Cs Activity with Pinhole Gamma Camera

Abstract

The gamma camera is a useful measuring device for grasping the distribution of contamination, but estimating the radioactivity of contamination is difficult. If the total energy absorption peak count rate of γ-rays can be measured with a pinhole gamma camera, we should be able to estimate the radioactivity. We can calculate it analytically by using the distance between the source and measurement points, and the peak count rate of direct γ-rays. The estimation method of ¹³⁷Cs radioactivity using a pinhole gamma camera was studied using Hitachi’s gamma camera (HDG-E1500), which can be used to measure the total energy absorption peak count rate of γ-rays.