ALPHA-PULSE HEIGHT DISTRIBUTIONS WITH ZNS(AG) SCINTILLATOR

A flask coated with ZnS(Ag) scintillator is one of the most accurate detectors available for measuring Rn-222. To maintain this accuracy, the counting system consisting of a photomultiplier tube and associated electronics must be checked on a regular basis. A combination of an alpha source and a ZnS(Ag) scintillator is commonly used for these purposes. This paper compares the pulse height distributions of 4 alpha sources with the pulse height distribution from a 100 cm(3) scintillation flask containing Rn-222. The source that most closely reproduced the distribution from an actual Rn-222 sample in a 100 cm(3) scintillation flask consisted of a sealed flask, of the same type, which contains a small piece of uranium-ore.