A One Trap, Two Luminescence Centre TL Model

The differential equations governing the behaviour of a model of the TL process in the presence of two luminescence centres and only one thermally active electron trap have been solved numerically. An additional deep trap not communicating thermally with the conduction band is included. At low temperatures and, for glow curves, for low temperature rise rates the well known quasi-steady state regime applies. At sufficiently high temperatures, however, exhaustion of the electrons in the active trap may take place and the quasi-steady state conclusions may be no longer valid. The simultaneous influences of both luminescence centres must be taken into account. In the quasi-steady state regime the familiar methods of determining the activation energy E from the data are valid even in the presence of two luminescence centres, provided exhaustion effects are not present and provided the recombination rates for the two luminescence centres do not differ by too much.