“…Different methods can be used to realize pulse-shape discrimination. We would like to refer to the optimal filter method proposed by Gatti and De Martini [225], and developed in [226] for CdWO 4 crystal scintillators, and then successfully applied to many scintillators [205,229,210,153,155,159,227,228,216]. In the optimal filter method, a shape indicator (SI) -a numerical characteristic -can be calculated for each scintillation event produced by a scintillator:…”