Mathematical formulation of T_(max)-T_(stop) method for LM-OSL and its experimental validation on α-Al_2O_3:C

摘要

A mathematical formulation and its experimental validation on α-Al_2O_3:C for evaluating the number of OSL components has been described. The method consists of various partial bleaching steps of LM-OSL curve and as a result, the peak position (T_(max)) of the resultant curve shifts if the system contains multiple components. However, for single component system the peak position of the resultant curve doesn't change on partial bleaching for a phosphor obeying first order kinetics. The method has been theoretically formulated for single and multiple component system with different order of kinetics and validated experimentally on the commercial α-Al_2O_3:C OSL phosphor. The slope of the curve between shift in T_(max) and bleaching time gives the number of the OSL components and measure of their closeness in terms of photoionization cross-section. Based on this result, the photoionization cross-section of the two embedded peaks in the LM-OSL curve of α-Al_2O_3:C were found to be 1.51 × 10~(-18) cm~2 and 5.02 × 10~(-19) cm~2 using CW-OSL and NL-OSL method.