The thickness of charged-particle emitting sources can be determined by varying the incidence angle of particles using silicon semiconductor detectors. The differences in energy between the peaks for an alpha emission measured with different incident angles are due to the energy loss of alpha particles in the source. These shifts can thus be used to estimate the source thickness. A new detection chamber has been constructed for this purpose. Its advantage is the registration of the alpha particles emitted from a given source using up to three different detectors simultaneously. Monte Carlo simulation was used to help to determine the best measurement conditions and interpret the results.