BH1216 III two-sample low-background α and β scintillation counter

This report describes an α and β radiation detection system capable of counting emissions from two samples simultaneously. Thin plastic phosphors and zinc sulphide phosphors are used as primary detectors, shielded against background radiation by a single plastic scintillator guard detector coupled in anticoincidence with the primary detectors. 239Pu α counting efficiency is 72% with a background of 1.59 counts per hour. 90Sr-90Y β counting efficiency is 45% with a background of 1.11 counts per minute