Motion of F Centers in KCl and KI

Abstract
The drift velocity of F centers in KCl and KI as a function of temperature is determined. The electric field producing this motion in the colored portion of the crystal is measured directly. The electric field in the uncolored region is found to be appreciably higher than the field in the colored portion. The thermal ionization energy for F centers is found to be 2.4 eV for KCl and about 2.0 eV for KI.