Detecting Gamma Radiations with a Geiger

After discussing the detection of alpha and beta radiations, this Section addresses the problem of detecting energetic photons (gamma rays) with a Geiger counter. They interact with matter differently from charged particles and the removal of energetic photons from a beam follows an exponential law with the thickness of the absorber material. Measurements with 0.662 MeV photons from 137Cs source and a Geiger counter are employed to demonstrate the different absorption properties of materials for such probes.