Gamma spectrometry is a multi-element analysis technique allowing to obtain the different-energy gamma radiation spectrum emitted by radioactive isotopes, the latter being registered by a photon detector. It’s based on photons producing charge carriers (electron-hole excitations) freely moving within the semiconductor to the collection electrodes.
They use the light-emission property of some materials when their free electrons produce excitations which later de-excite after the passing of ionising radiation. The emitted light turns into an electric signal that’s later measured with a photomultiplier.
A proportional counter is an ionising particle detector. Its operation is based on the ionisation produced in particles by an intense electric field passing through the gaseous detection volume. Both radiation types can be simultaneously measured taking into account that, by passing through a material medium, an alpha particle produces a higher specific ionisation than a beta particle of equal energy.
