The use of silicon photodiodes for radon and progeny measurements

Abstract

Reduced cost, high quantum efficiency and very good detection characteristics of PIN silicon photodiodes made possible their utilization for alpha particles detection. This paper presents different studies and applications of this type of detector for qualification and quantification of radon and its progeny in laboratory and in the field. Since photodiodes are sensitive to environmental electromagnetic fields, protecting cells were adapted for use around the detector. A small three-channel (2-5.5 MeV; 5.5-6.5 MeV; 6.5-8.2 MeV) portable alpha counter was developed that allows the determination of the radon concentration and the radon exhalation rate. Numerous field applications were conducted in different conditions (uranium waste storage, dwellings, etc.) where this simple and inexpensive instrumentation demonstrated very good performance, reliability, and easiness of operation while measuring radon concentrations from 50-100 Bq m(-3) to several MBq m(-3).