RADIATION INDUCED THERMOLUMINESCENCE IN CaF2:Tm DETECTORS.

The fact that in CaF//2:Tm, thermoluminescence (TL) glow peaks occurring at different temperatures have different sensitivities to low and high LET radiations, has been found useful for the simultaneous and separate determination of fast neutron and gamma ray absorbed doses from therapeutically used neutron beams. The gamma ray and fast neutron responses of the individual glow peaks are found to be additive for separate and successive irradiations. A glow peak at 150 degree C which has a relatively smaller sensitivity to densely ionizing radiations, exhibit reduced sensitivity to high doses of even low LET radiations (**6**0Co gamma rays). On heat treatment, the relative TL responses of 110, 150 and 240 degree C glow peaks are found to reduce in different proportions. In view of the present study, the various explanations for the difference in LET dependences of the glow peaks have been analyzed.