Beta Absorption Experiments with Geiger Counters

The absorption of electrons emitted by a beta radioactive source through different materials may be investigated by means of a Geiger counter. Measurements of the residual flux of electrons transmitted through layers with increasing thickness may be analysed to extract the value of the absorption coefficient. As an example, a set of such measurements performed using a simple DIY Geiger counter and a small activity 90Sr beta source is here discussed.