Method for Determining an Unknown Absorbed Dose of Radiation Using Optically Stimulated Luminescence

Abstract

A bimodal method for determining an unknown absorbed dose of radiation. An irradiated material is illuminated with ultraviolet or visible light and the luminescence which is emitted from the material is detected. The illuminating light is pulsed, with pulse widths varying from 1 ns to 500 ms. The luminescence emission from dosimetric traps is monitored after a delay following the end of the illumination pulse. The integrated luminescence signal is related to the initial absorbed dose of radiation and thus may be used to calculate the unknown absorbed dose after calibration. In a first mode, the material is completely detrapped--that is, all the dosimetric traps are emptied by the illumination beam. In a second mode the number of illumination pulses, each being followed by the time delay and by periods during which the luminescence signal is detected, is selected such that only a portion of the radiation-induced luminescence from the material is extracted.