Optically Stimulated Exoelectron Emission from Potassium Chloride Single Crystals

Potassium chloride single crystals are irradiated with a 3 ke V electron beam, and the optically stimulated exoelectron spectra (OSEE) are studied as a function of dose, temperature, and energy in the range from 300 to 650 nm. Optical extinction spectra are measured simultaneously with the OSEE spectra. The exoemission spectra seem to show exoemission peaks corresponding to the F and K optical absorption bands. In addition an emission peak appears at about 400 nm within the high‐energy tail of the K‐band. Emission lineshapes are narrower than extinction lines and peak positions do not exactly correspond. With increasing surface damage the F‐band emission diminishes. Increasing temperature produces a shift in the F‐band to longer wavelengths and an increase in intensity.