Thermoluminescent Sensitivity of CaF2

The thermoluminescent sensitivity of CaF2:Mn in a mixed field of thermal or fast neutrons and gamma rays as a function of both components of the irradiation has been studied. No permanent change in TL sensitivity for gamma rays has been found after irradiation with thermal neutron fluences up to 4 × 1012 n/cm2 and fast neutron fluences up to 8 × 1013 n/cm2. CaF2 irradiated with 137Cs gamma rays followed or preceded by a fast neutron irradiation did not show significant differences in TL response. A model has been developed to explain the fast neutron sensitivity observed and the apparent dependence of this sensitivity on neutron energy is discussed.