Studies on Nonmetals During Irradiation: The Growth of F Centers in KCl at 85°K

Curves of KCl $F$ center versus dose, obtained by making absorption measurements during irradiation with ${\mathrm{Co}}^{60}$ $\ensuremath{\gamma}$ rays at 85\ifmmode^\circ\else\textdegree\fi{}K, are accurately described by $\ensuremath{\alpha}(t)={A}_{1}[1\ensuremath{-}\mathrm{exp}({a}_{1}t)]+{\ensuremath{\alpha}}_{L}t$. After irradiation, the coloring decays less than 1% in 8\ifmmode\times\else\texttimes\fi{}${10}^{4}$ sec. ${A}_{1}$ is independent of, and ${a}_{1}$ and ${\ensuremath{\alpha}}_{L}$ are proportional to, the dose rate. These observations are in accord with a particularly simple phenomenological theory of radiation-induced color-center formation.