Thermoluminescent Kinetics of Alpha-Irradiated Alkali Halides

The kinetics of the thermoluminescence of single crystal NaCl, KCl, and KBr irradiated with 40‐MeV alpha particles were investigated. Only one glow peak, composed essentially of a single emission band, was obtained for each of the salts investigated. To attempt complete analysis of the kinetics, both glow curve and isothermal annealing experiments were employed. The results from glow curves were shown to be unreliable for calculation of the kinetic order in the case of NaCl and KBr. The isothermal tests indicate the kinetics of the dominant process for NaCl to be first order; for KBr, first order; and for KCl, $\frac{3}{2}$ order. No general statement can be made concerning the order of these processes; thus, at present, the kinetics for each salt investigated must be determined individually. Occasionally, secondary processes occur in specimens of NaCl and KBr, even though essentially only one spectral peak was detected. A simple model for luminescence will explain the kinetics of NaCl and KBr; it involves activation of electrons from traps into the conduction band. To explain the results for KCl, a more complex model is required. Activation energies were also calculated.