Storage phosphors for thermal neutron detection

The main requirements on neutron detectors based on storage phosphors (SPs) are formulated. It is shown that commercial gadolinium-containing neutron SPs (Gd-SPs) based on mixtures of BaFBr:Eu2+ with Gd2O3 (a neutron converter) do not possess optimum neutron characteristics because of a high sensitivity to gamma radiation. A comparative study of photostimulated luminescence (PSL) kinetics was performed for samples of halogen-containing borates Sr2B5O9Br(Cl) and Ca2B5O9Br(Cl) activated with Ce3+ ions and of the commercial Gd-SPs upon neutron and gamma irradiation. The results suggest that the PSL characteristics of the above borates with 100% content of 10B must be similar to those of Gd-SPs. Use of the halogen borates as SPs offers an advantage to Gd-SPs, because the former neutron detectors are less sensitive to gamma radiation.