Measurements of the Energy of Beta- and Gamma-rays with a Scintillation Counter

Abstract

Broser and Kallmann¹ have shown that mono-energetic alpha-particles give pulses of the same height in a scintillation counter, and that the pulse-height is proportional to the energy of the alpha-particles. It is found in studying the pulses for some beta-radiating substances that there is proportionality between pulse-height and energy also in this case. The same result is obtained when studying the pulse-height from the gamma-rays emitted by different substances. There is, in this case, a continuous distribution of pulses from zero to a certain maximum height which corresponds to the continuous distribution of Compton electrons produced in the absorption of the gamma-rays. By determination of the end-points of the distributions, a rough measure is given of the energy of the gamma-rays. Recently Jordan and Bell² have published some measurements of that kind. This method gives rather uncertain results, especially for gamma-spectra with more than one energy. I have therefore tried to determine the pulse-height corresponding to those photo-electrons which are created at the absorption of the gamma-rays in the phosphor.