The influence of pre- and post-irradiation annealing on LiF:Mg,Cu,P stability

The influence of pre- and post-irradiation annealing procedures on LiF:Mg,Cu,P (trade name MCP-N) thermoluminescent detector stability was investigated. The detectors were processed in four groups, undergoing complete or incomplete preparation cycles (containing pre- and/or post-irradiation annealing in various combinations). Each cycle was repeated 10 times. The decrease in the stability was observed in groups with pre-irradiation annealing procedure, and not observed in other groups that were found to be apparently stable. The influence of the thermal history on the properties of the detectors was also investigated by swapping the chosen groups of detectors with respect to the annealing cycles. Changes in the properties of the detectors were observed after next 10 cycles of measurements too. Exponential model was proposed to describe the trends observed at two parts of the experiment. Its application for the dose corrections related to the cycle number of the readout improves the accuracy of final dose determination. (authors)