Prof. Reuven Chen has been working on different aspects of luminescence in solids. In particular have been studied thermoluminesnce (TL), optically stimulated luminescence (OSL) and radioluminescence (RL). Different aspects have been studied theoretically to explain various effects previously reported in different materials, in particular materials involved in the applications in dosimetry and in geological and archaeological dating such as quartz, feldspars, LiF and Al2O3. The methods used included numerical simulations consisting of the numerical solution of the relevant simultaneous differential equations as well as analytical approximate solutions and Monte Carlo simulations.
Research achievements include: explanation of the non-linear dose dependence of TL and OSL including strong superlinear and sublinear dependencies; dependence of these phenomena on the dose-rate effect; models of concentration quenching and thermal quenching of TL; linear-modulated-OSL (LM-OSL); thermally assisted OSL (TA-OSL); stability of the TL and OSL signals; normal and anomalous heating-rate effects of TL; a model of thermally-transferred OSL (TT-OSL).
Future work planned: Effects associated with two-electron traps and of two-hole centers; competition between excitation and fading of TL and OSL using Monte Carlo simulation; signals from a random distribution of defects.