No abstract

A new set of expressions is derived to evaluate the thermal activation energy (E) of general order thermally stimulated luminescence (TSL) peaks. The expressions derived involve temperatures at which the intensity of the peak is 1/2, 2/3, and 4/5 th of the maximum, andthe peak temperature (Tm). The validity of the formulae based on Tm, T1 (low half‐intensitytemperature), and T2 (high half‐intensity temperature) is demonstrated by comparing the values of E, obtained by using the present expressions, with those of Chen. Taking into considerationa large number of possible cases, it is shown that the value of E obtained by using the expressions involving T1 and Tm, T2 and Tm, and T2 and T1 are not only in excellent agreement amongstthemselves but also with that of the actual value.

A new set of expressions have been derived to evaluate the thermal activation energy, E, of a thermoluminescence (TL) peak. The order of kinetics, b, of the peak may be first order (b=1), second order (b=2) or general order for which the authors have taken b=1.5 as an example. The derived expressions involve temperatures at which the intensity of the peak is 1/2, 2/3, 4/5 of the maximum and/or the peak temperature (Tm). The selection of these points is based on the fact that the upper half of the peak is free from interference of the satellite peaks. The applicability of these expressions has been checked by applying them to some typical experimental TL peaks. The value of E determined by using these new sets of expressions is in good agreement with that found by curve fitting.

No abstract

Electron and positron impact di †erential cross sections for excitation of the 3s state of a hydrogen atom from its metastable 2s state are calculated in a distorted wave approximation at 10 and 50 eV. The e †ects of both adiabatic and non-adiabatic distortion of the atomic charge cloud by the incoming electron or positron are included in the initial and Ðnal state wavefunctions. Contrary to an earlier prediction, no dramatic di †erences between the electron and positron results are found.