Evaluation of granulated BGO, GSO:Ce, YAG:Ce, CaF2:Eu and ZnS:Ag for alpha/beta pulse shape discrimination in a flow-cell radiation detector

Granulated BGO, GSO:Ce, YAG:Ce, and CaF2:Eu; CaF2:Eu coated with a fluorescent polymer, and combinations of coated and uncoated CaF2:Eu with ZnS:Ag were evaluated for their ability to discriminate between alpha and beta particles in a flow-cell radiation detector. The evaluations were based on the analysis of pulse shape spectra. Various granulated scintillators were packed into flow cell detectors that were coils of 3.0 mm OD×1.5 mm ID fluorinated ethylene propylene Teflon® tubing positioned between dual photomultiplier tubes for analysis. The best pulse shape discrimination was obtained for a combination of equal masses of uncoated CaF2:Eu (63–90 μm) and ZnS:Ag (10 μm), which had a 9% spillover. Additional research is needed to reduce the spillover.