Dosimetric characterization of highly sensitive OSL phosphor: LiCaAlF6:Eu,Y

The paper presents the dosimetric characterization of lithium calcium aluminum fluoride doped with europium and yttrium (LiCaAlF6:Eu,Y), synthesized by simple melt process. The characterization involved thermoluminescence (TL), optically stimulated luminescence (OSL), photoluminescence (PL) spectra, OSL emission spectra, minimum measurable dose, fading, dose response and photon energy dependence measurements. The OSL sensitivity of this phosphor to ionizing radiation was found to be ∼20 times to that of commercially available Al2O3:C, whereas, the TL sensitivity was ∼2.5 times to that of CaSO4:Dy (0.05 mol%). Photoluminescence (PL) and OSL emission spectra suggest that the Eu2+ ions are responsible for OSL emission. The reusability of OSL discs for 50 cycles for a test dose of 20 mGy has been established. Minimum detectable dose for the phosphor in continuous wave OSL (CW-OSL) mode was found to be 0.5 μGy with negligible fading post 9 days of irradiation. Owing to its excellent dosimetric characteristics the phosphor is a highly sensitive dosimetric grade phosphor and is a serious contender for various radiological applications.