Scintillation Properties of 1 Inch ${\rm Cs}_{2}{\rm LiYCl}_{6}{:}{\rm Ce}$ Crystals

We have grown and investigated 1 inch diameter (CLYC) crystals for gamma and neutron detection. The samples provided excellent results. For example, 5.1plusmn0.1% energy resolution was obtained at 662 keV (5.5% at 511 keV). The light output of 4500plusmn350 photoelectrons/MeV (PMT, Hamamatsu R6233) was measured. The samples also showed excellent plusmn1.2% non-proportionality in the 14.4 to 1274 keV range. This suggests a possibility for even better energy resolution with a superior photodetector. The intrinsic energy resolution of investigated crystals was estimated to be 2.1%. The neutron detection was also confirmed. The neutron peak was observed at about 3.2 MeV (gamma equivalent) and its resolution was 2.9plusmn0.1%. Gamma-neutron pulse shape discrimination was also achieved.