SENSITIZATION AND SUPRALINEARITY OF CAF2 - NATURAL THERMOLUMINESCENT PHOSPHOR - INTERPRETATION BASED ON PARTIALLY INTERACTIVE TRAPS

The partially interactive trap system model is applied to the response of the main glow peak in the thermoluminescence of the CaF2: natural phosphor. The value of the trap filling constant alpha, defined as the fraction of traps filled per unit dose, is found to be 2.6 x 10(-3) Gy-1. The ratio K between the interactive and non-interactive trap populations is found to be 2.4. This means that 70% of the traps of the glow peak are interactive with the thermally disconnected deep traps. These quantities are obtained from the response of the pre-dose sensitized phosphor. Pre-exposure renders the interactive fraction of traps non-interactive. This, in turn, leads to sensitization. Supralinearity also is the result of the same process. The experimental results on supralinearity and sensitization are compared with the theoretical predictions using the above parameter values of alpha and K. The theoretically predicted curves agree within 25% with the experimental results.