Abstract. A simple relation for the destruction temperatures Td of the HA centres (H centres trapped by an impurity cation) as a function of the difference in the radii for a host cation and impurity in alkali halide crystals is presented and theoretically justified. This relation allows to predict Td for H centres trapped by other monovalent cation impurities.
Solid State Communications, Vol.106,1998, pp.289-291

LiF and NaCl crystals were irradiated at 8 K and 300 K with various light and heavy ions C, Ti, Ni, Kr, Sm, Au, Pb, and U of kinetic energy between about 50 and 2600 MeV, providing electronic energy losses from 0.7 to 26.4 keV/nm. A cryostat installed at the beamline allowed in situ absorption spectroscopy and thermostimulated luminescence TSL measurements from 8 K upward. Creation of electron and hole color centers is analyzed as a function of irradiation temperature, fluence, and thermal and optical bleaching. Anion interstitials I and H centers were only observed in crystals irradiated at 8 K. These defects are unstable and disappear in the temperature range 10–100 K. For heavy ions Au, U, the F-center accumulation efficiency at low fluences is larger at 8 K than at room temperature. The opposite effect is observed for light ions C, Ti, Ni. The results are discussed within the frame of transient heating influencing separation or annealing of point defects.
Phys. Rev. B 78, 024120 (2008)