Effects of cerium concentration in Tl 2 LiYCl 6 scintillation detectors

Cerium doped Tl 2 LiYCl 6 (TLYC) is a new, Tl-based elpasolite scintillation detector. TLYC crystals with 0%, 0.5%, 3%, 5%, and 9% cerium concentrations have been grown. Emission spectra of TLYC with these different Ce concentrations peak between 430 and 445 nm. Energy resolution values of 6.8%, 5.2%, 4.2%, 3.9%, and 4.4% at 662 keV (FWHM) are measured for TLYC doped with 0%Ce, 0.5%Ce, 3%Ce, 5%Ce, and 9%Ce concentrations, respectively. Comparison with a 137 Cs spectrum collected with a NaI:Tl results in gamma-ray induced light yields of 18,000 ph/MeV for 0% Ce, 27,000 ph/MeV for 0.5%Ce, 27,000 ph/MeV for 3%Ce, 30,000 ph/MeV for 5%Ce, and 28,000 ph/MeV for 9%Ce.