抄録
The formation and decay of color centers in alkali halides have been studied using a pulsed electron beam. The F and V-type bands reach maximum heights in optical density at the end of the radiation pulse. Vk and V1 bands in KBr appear to show the first order decay kinetics; their room temperature life times are 1.3 and 3.8 μsec, respectively. A fraction of F and F′ bands bleach by the annihilation with migrating Vk centers. The activation energies for the disappearance of H, V1 and Vk centers in KBr are found to be 0.09, 0.25 and 0.39±0.02 eV, respectively. A fraction of H centers in KCl decays with a temperature independent time constant (∼0.13 μsec) which is due to the tunneling with nearby F centers. In crystals containing U-centers (H− ions) the F band continues to grow for several microseconds after the pulse. Absorption bands which decay with the same time constant as the F band growth have been found at 775 mμ (KBr) and 725 mμ (KCl).
