COMPTON-SCATTERING, THE ELECTRON MASS, AND RELATIVITY - A LABORATORY EXPERIMENT

compton scattering in a semiconductor detector is used to ''discover'' the relativistic relation between energy and momentum and to demonstrate the dependence of p, E and gamma on beta. The motivation is to measure the (rest) mass of the electron, and this can be done to within 1 keV with a commonly available set of gamma ray sources. To determine precisely where the Compton edge occurs in a spectrum, a Monte Carlo calculation of detector response is described which also helps the student to understand the physics of the detection process.