Investigation on the Gamma-Rays Induced Radiation Damage Effect of LaBr₃:Ce and CeBr₃ Crystals

This work investigates gamma-rays induced radiation damage effect in LaBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>: Ce and CeBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> crystals. Optical and scintillation properties of these crystals were characterized before and after irradiation up to 2×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> rad. The recovery of radiation damage was observed in both crystals. After the crystals were irradiated at various dose rates, it is confirmed the radiation damage saturation cannot be attributed to the dose rate dependent effect. After the irradiation up to 2×10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> rad, the loss of emission-weighted longitudinal transmittance (EWLT) values is approximately 4.7% for LaBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>: Ce and 6.0% for CeBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>. Meanwhile, the light yield (LY) loss of LaBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>: Ce and CeBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> crystals is approximately 12.3% and 11.6%, respectively. The excellent correlation between EWLT loss and LY loss indicates the LY degradation in the both crystals can be mainly attributed to the loss of transmittance. The deterioration of energy resolution (ER) after 2 Mrad irradiation ranges from 5.1% to 6.7% for LaBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>: Ce and from 8.7% to 9.5% for CeBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>. The decay time is not affected by radiation damage. Compared with other scintillation crystals, LaBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>: Ce and CeBr<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> crystals are radiation hard. These findings provide important insights into the behavior of these materials working at severe radiation environments, which is essential for their applications and production.