Evaluation of alpha/beta pulse shape discriminating flow-cell radiation detectors using BGO, GSO, YAG:Ce, YAP:Ce, CsI:Tl, and CaF2:Eu

A technology involving the combination of ion chromatography and on-line scintillation counting to measure non-gamma-ray emitting radionuclides has been demonstrated with aqueous samples of moderate activities, ∼20 to 80 Bq per radionuclide. For this technology to be useful at environmental levels, detection limits must be lowered. Reduction of the minimum detectable activity when measuring alpha-emitting radionuclides is achieved by lowering the background (b and g) events. One technique for lowering the background is the incorporation of alpha/beta pulse shape discrimination (PSD) circuitry into the flow-cell detector design. Flow-cells typically consists of 63-90 mm scintillator particles packed into a transparent Teflon tube. The radioactive solution (separated by element through ion chromatography) flows through the interstitial space of the flow-cell