Simultaneous estimation of exposure and time elapsed since exposure using multipeaked thermoluminescent phosphors.

Knowledge of the time elapsed since a radiation exposure may be useful in personnel monitoring, as for example in determining the time for occurrence of an over exposure or a nuclear accident, or in the choice of a therapy procedure, etc. This paper describes the application of the multipeaked thermoluminescent phosphors, such as natural CaF2, and Harshaw's type of LiF, for the simultaneous estimation of the exposure and the time elapsed since this exposure. Natural CaF2 used for this purpose has three types of traps, so that the glow curve shows three maxima at about 100, 180 and 260 degrees C.