Abstract

Cerium-doped lutetium yttrium oxyorthosilicate (LYSO:Ce) crystals are known to have considerable variation in scintillation light yield. Thus, the use of long LYSO:Ce crystals in energy measurements requires improved uniformity to realize high resolution. As it is known that differences in crystal characteristics can originate from differences in manufacturing techniques using the Czochralski method, it is useful to measure and compare the non-uniformity of LYSO:Ce crystals from different manufacturers. Comprehensive comparison of such crystals can be achieved using two methods, namely, gamma spectroscopy and optical spectroscopy. In this study, we examined two long crystals obtained from Saint-Gobain (France) and JT Technology Co. Ltd. (China). The Saint-Gobain crystal was found to have a more uniform distribution of scintillation properties and to contain fewer optical traps and crystal structure defects.