Doped Lead Fluoride Chloride Crystals for the HHCAL Detector Concept

We report an investigation on pure and doped PbFCl crystals. Optical and scintillation properties, such as emission and transmittance spectra, light output and decay kinetics, were measured at different temperatures. Three emission bands at 2.27, 2.85 and 3.39 eV are observed at 77 K. Thermal quenching effect is also observed. While a scintillation component peaked at 400 nm with 3 ns decay time is observed in all PbFCl samples, a secondary emission at 550 nm with 360 ns decay time is found in the K doped PbFCl samples. The origins of three emission bands and further development of PbFCl for the HHCAL detector concept are discussed.