Latest growth of large diameter Tl-based elpasolite scintillation crystals

Elpasolite scintillators play an important role in radiation detection and imaging. Novel Tl-based elpasolite scintillators such as Ce-doped Tl2LiYCl6 (TLYC) have been developed as excellent Tl-based dual mode gamma and neutron detectors. This paper presents a successful high yield growth and gamma-ray characterization of large diameter (1-inch to 1.5-inch diameter) single, crack-free, and transparent TLYC crystals at Fisk University. Energy resolution of 4.2% (FWHM) at 662 keV and light yield of 26,000 photons/MeV are measured. As-processed and hermetically packaged TLYC samples are characterized for their gamma-ray energy resolutions, light yields, non proportionality behaviors and decay times. Successful growth of 1-inch diameter (Cs,Tl)(2)LiLaBr6:Ce crystals are also shown. The best result is obtained when the content of Cs+ is larger than Tl+. Energy resolution of 3.4% (FWHM) at 662 keV is measured for (Cs,Tl)(2)LiLaBr6:Ce for 75% Cs-to-25% Tl ratio.