Recent development in OSL phosphors and associated instruments in BARC

Worldwide there is a discernable shift in paradigm as far as personnel dosimetry is concerned. Conventional TL approach towards radiation measurement is being gradually replaced by OSL. I will discuss the factors which have motivated these changes and related material development issues with a specific focus on Al2O3, based systems namely α-Al2O3:C and YAG. The OSL mode of readout offers an interesting opportunity for the remote measurement of dose, further it also promises an all-optical setup for the luminescence measurement as the need to heat the sample is summarily obviated. Conventional method for synthesis of α-Al2O3:C is fraught with the problems, in that, there is little or no control over the defects formation which are vital to its OSL sensitivity. We at BARC have recently developed an alternative approach towards the synthesis of α-Al2O3:C phosphor where a plain crystalline alumina plate is sintered in high vacuum at elevated temperature in the presence of graphite. The implications and consequences of this development are discussed in the talk. The talk also covers the efforts directed towards the indigenous development of related instrumentation for TL/OSL measurements. (author)