Correlation between Thermally Stimulated Exo-Electron Emission and Thermoluminescence of Pure LiF Single Crystal

Abstract

Simultaneous measurements of thermally stimulated exo-electron emission (TSEE) and thermoluminescence (TL) of pure Lit single crystal X-irradiated at liquid nitrogen temperature (LNT) are made over the temperature range from LNT to ∼300°C. A close correlation between TSEE and TL is observed at low temperature. Optical repopulation studies, and spectral measurements of TL and luminescence under X-irradiation indicate that the TSEE at low temperature is related to the emission processes of 240∼290 nm band, which dominate the X-ray produced TL at low temperature and are associated with hole traps. This emission band may arise from a radiative decay of self-trapped-exciton resulting from the recombination of a self-trapped-hole and an electron. The TSEE at low temperature may be explained in terms of a kind of "Auger effect" and/or photoelectric emissions.