INFLUENCE OF IRRADIATION RATE ON PRODUCTION OF F CENTERS IN LIF (TLD GRADE)

Optically polished samples of extruded plaques of LiF (TLD grade) were given 60Co gamma-ray exposures ranging from about 35 000-450 000 R, at exposure rates between about 1.5×103 and 5×10 6 R/h. Over this range of exposures and exposure rates, the resulting absorption in the F band was found to be independent of exposure rate, and to increase with exposure, even for exposures for which the thermoluminescence exhibited saturation effects. After thermoluminescence readout at about 235°C, practically all the absorption in the F band created by the 60Co gamma-ray exposures had disappeared. These results are compatible with the dominant role given F centers in some of the current models for the thermoluminescence process in LiF (TLD grade). © 1969 The American Institute of Physics.