Growth problems, thermal expansion and scintillation properties of Ce:Li6Lu(BO3)3 crystals under thermal neutron excitation

The problems of the growth of Ce:Li6Lu(BO3)3 (LLBO) crystal using Czochralski technique have been discussed. The supercooling, cleavage crack and inversion of solid-liquid interface were the main problems to grow high quality LLBO single crystals with fully transparent ingot. The thermal expansion coefficients of LLBO crystal were obtained from HTXRD data: αa=23.9×10−6/°C, αb=27.8×10−6/°C and αc=9.3×10−6/°C. The LLBO crystal with thickness of 1 mm grown from natural raw materials was sensitive to thermal neutrons and insensitive to high energy gamma rays (137Cs). The decay time was statistically recorded to be about 38 ns by the digital oscilloscope. Therefore, LLBO crystal will be a promising fast scintillator for neutron detection.