Improvements and problems of Bridgman-Stockbarger method for fabrication of TlBr single crystal detectors

TlBr is a promising material for gamma-ray detectors; however, it has crystal quality problems originated from the crystal growth itself and further treatments during detector fabrication. The effect of technological improvements on crystal quality has been studied in this work. Low performance of studied detectors was shown to be associated with residual stress or/and small-angle grain boundaries in these crystals. Several crystals failed as detectors were proved to contain impurities.