Photoproduction ofV1Centers in KBr Crystals

KBr crystals have been irradiated with monochromatic light of a wavelength of 190 millimicrons at liquid nitrogen temperature. When an electric field is applied to the crystal and its temperature subsequently raised, a burst of current is observed at — 150°C, which corresponds to the destruction of $V_1$ centers. Evidence is presented that $F$ centers and $V_1$ centers are created simultaneously by absorption of photons in the tail of the fundamental band of the crystal.