Optimization of data acquisition parameters for single gamma line sensing: KSr2I5:Eu2+ and NaI(Tl) compared

Abstract

Abstract KSr2I5:Eu 2 + scintillators exhibit better than 3% energy resolution at 662 keV and may be significantly less expensive to produce than other, similar energy resolution scintillators. However, KSr2I5:Eu 2 + exhibits a 6.5 Bq/cm3 intrinsic background from the presence of 40K. This background is not only the well-known 1.46 MeV gamma, but also the 1.31 MeV end point of the beta spectrum. This paper computationally evaluates the optimum data acquisition parameters of KSr2I5:Eu 2 + and compares them to NaI(Tl) for the detection of single line gamma sources between 0.01–2.2 MeV with incident source strengths between 5 s−1 and 100 s−1 striking the detector. We found a strong dependence of the time-to-detection on the data acquisition parameters, where the time-to-detection of KSr2I5:Eu 2 + was 1–3 times larger than NaI(Tl) across the parameter space. The largest discrepancy observed was between 0.6 MeV and 1.2 MeV, where the intrinsic 1.31 MeV beta dominates the background.