RbGd Br : Ce Scintillators for Gamma-Ray and Thermal Neutron Detection

In this paper, we report on gamma-ray and thermal neutron detection with RbGd Br : Ce scintillators. RbGd Br : Ce (RGB) is a new scintillator material that shows high light output (56 000 photons/MeV) and has a fast principal decay constant (45 ns) when doped with 10% Ce. These properties make RGB an attractive scintillator for -ray detection. Also, due to the presence of Gd as a constituent, RGB has a high cross-sec- tion for thermal neutron absorption and can achieve close to 100% stopping efficiency with 0.5-mm-thick RGB crystals. Crystals of RGB with three different Ce concentrations (0.1, 5, and 10%) have been grown. Their basic scintillation properties such as light output, decay time, and emission spectrum have been measured. In addition, high-efficiency thermal neutron detection has been confirmed in our studies.