Beta spectroscopy with a large-area avalanche photodiode module and a plastic scintillator

Beta spectroscopy utilizing a large-area avalanche photodiode module (LAAPD) and a plastic scintillator is investigated. Beta-emitting radionuclides including 36Cl, 90Sr/90Y, and 99Tc are detected in the plastic scintillator that is coupled to the LAAPD. The detector system is capable of recording energies as low as about 60 keV before noise becomes significant. The LAAPD by itself, without the scintillator present, is well suited to detecting beta particles, enabling it to act as a counter or rate meter. Some spectroscopic information can be gained for low-energy beta emitters, such as 14C, that are measured directly by the LAAPD.