Large-Size CsI:Na Single Crystals for Future High Energy Physics Experiment

With the development of deep space exploration, nuclear medical imaging, high-energy physics experiments, and other fields, the demand for large-size CsI:Na crystals is increasing due to the low cost of use, high light yield, and excellent irradiation resistance of CsI:Na crystals. In this work, we investigated the scintillation characteristics of thirty-five Ø76 mm × 76 mm CsI:Na single crystals, delving into the variation of energy resolution and light yield. Meanwhile, a method based on 137Cs source collimation and coupling the crystal to PMT in different directions was used to reveal the uniformity of scintillation performance of large-size CsI:Na single crystals. The Bridgman-grown 51 mm × 51 mm × 152 mm CsI:Na single crystals have an energy resolution of 6.5% at 662 keV, which does not change significantly regardless of irradiation location or irradiation method.