抄録
The absorption spectra ranging from 360 to 960 mμ were measured on rock salt crystals bombarded with electrons at various temperatures. Three types of color centers, namely F, 590 mμ and colloidal centers were formed as a function of specimen temperature during bombardment. The thermal bleaching of these three color centers was also investigated.
From these results it is supposed that the color center with an absorption peak at about 590 mμ may correspond to a precursor of colloidal sodium. It is also suggested that there may be a correlation between coloration and dissociation of sodium chloride by electron bombardment.
