Simulation of H-centre migration along dislocation lines applied to UV-induced afterglow in Eu doped alkali halides

In this work we have simulated the migration of H centres along dislocation lines and their recombination with F_z centres after a pulse irradiation. The variable parameter in our simulations was the probability p of recombination between H and F_z centres when they meet. The results of the simulation for p = 1 were in good agreement with a previous derived approximation and with the experimental data. We found that the function I = I₀ n^-α could be fitted very well to the afterglow decay for all p values. The afterglow yield, defined as the total amount of afterglow, divided by the total amount of generated precursors of the H-F _z pairs was found to decrease with increasing p. The exponent α however was found to be remarkably stable at 1.49 over a range of p from 1 to 0.2 below which it decreases to 0.5.