Stored energy and colourless centres in alkali halides

A stored energy of around 1020 eV g-1 has been found to be induced by either plastic deformation or quenching in both NaCl and KCl samples. The corresponding energy release spectra up to 700 degrees C exhibit the same peaks as occur for heavily irradiated samples in which the total stored energy is also in the above indicated region. It is proposed that the radiation-induced colour centres, whatever aggregation state they may be in, are a minor part of the total radiation-induced defects.