Characterization of indigenous OSL phosphors LiCaAlF6:Eu,Y and α-Al2O3:C for space dosimetry

Abstract

The possibility of using indigenously synthesized Optically Stimulated Luminescence (OSL) phosphors, α-Al2O3:C and LiCaAlF6:Eu,Y is explored for application in space dosimetry. The dosimeters prepared using these phosphors were irradiated in BARC-TIFR Pelletron Accelerator facility with proton beam (8–20 MeV). The OSL properties with proton beam irradiation were compared with beta irradiation corresponding to 90Sr/90Y. No change in the OSL emission was found for both the phosphors when exposed to with low LET 90Sr/90Y beta (0.2 keV/μm) and high LET proton (2 keV/μm, 20 MeV). It was observed that Continuous Wave (CW) OSL signal decays faster with increasing LET of the proton beam for both types of dosimeters α-Al2O3:C and LCAF. The OSL dose response is linear for the high LET proton beam which is similar to the response obtained using low LET beta and gamma irradiation. The variation of OSL efficiency per unit fluence matches reasonably well with the theoretically calculated values of absorbed dose in water.