In recent year there has been a wide spread application of thermoluminescence detector (TLD) for a personnel dosimeter. Thermoluminescence is a complex process as it involves a trap center, a luminescence center and the transfer of a carrier from the trap center to the luminescence center by heating. Therefore, for the majority of thermoluminescent phenomena there has been given little knowledge about the atomic nature of the trap and luminescence center and the sort of the carrier transfered between them. In the case of LiF: Mg, moreover, there is a much better opportunity for the identifica-tion of the centers and the carrier because radiation effects on many pure alkali halide have been extensively studied. Since 1967, the effort to study the detailed nature of the centers and the carrier in LiF: Mg has been made by using optical absorption and bleaching methods. These researches are described here to be help to understand the basic thermoluminescent process and the role of another impurities in thermoluminescent materials is also refered. As many kinds of thermoluminescent materials are now prepared, the characteristics and the example for applications of these materials are explained.
Department of Applied Physics, Tohoku University Application of the many-body theory and development of SOR technique have revived the X-ray spectroscopy. A review is given on the recent progress made in the last 15 years as well as the basic understanding of X-ray spectra. Emphasis is put on the time-dependent and many-body nature of the spectra.
The magnetization-induced uniaxial anisotropy has been investigated in zero-magnetostrictive Permalloy films by isothermal annealing. The samples, evaporated and successively stabilized in a rotating magnetic field, are annealed in a dc magnetic field without breaking the vacuum after deposition. The annealing behavior of the developed anisotropy field Hk is found to consist mainly of two definitely separated stages; the one (the first stage) is observed at a low annealing temperature, 100°_??_200°C, while the other (the second stage) at a higher anneal-ing temperature, above 300°C. The present report is concerned only with the first stage. The analysis of the annealing process indicates that the activation energy has a continuous distribution ranging from 0.7 to 1.0 eV with a frequency factor of about 107sec-1. It is noted that neither of the two quantities are dependent to any extent on the stabilization treatment, but are highly responsible for the saturation value of the first stage Hkh. Here Hk1∞ decreases with increasing stabilization temperature and its time. A model to explain consistently these annealing features is also proposed.
The magnetization-induced uniaxial anisotropy in stabilized zero-magnetostrictive Per-malloy films is investigated by isothermal magnetic annealing at various temperatures above 300°C. The annealing kinetics are explained very well by a model assuming a continuous distribution of activation energy; the mean value of which is taken to be 2. 2eV, with a range of distribution of ±0. 13 eV, and with a frequency factor of 1014 sec-1. Thus the anneal-ing behavior may be interpreted as a reorientation of atom-pair ordering caused by the mi-gration of the thermal equilibrium vacancies, namely by self-diffusion.
A Penning type sputtering apparatus is constructed, in which sputtering is carried out at an argon pressure of 6×10-4 Torr. It is found that Au, Ag, and Cu films change from polycrystalline to single crystal structure as the temperature of NaCl substrate increases. The parallel orientations, (001) Au, Ag, cu//(001) Nacl,  Au, Ag, cu//(100) Naci are observed. Epitaxial temperature of the metals shifts to a high temperature region as the target potential increases. The growth sequence, epitaxy and particle density of the gold film are compared with those of the thermally evaporated gold film prepared at the argon pressure of 6×10-4 Torr. The results are discussed in terms of the energy of the depositing atoms and nucleation sites on the substrate. It is considered that the low epitaxial temperature is not due to high energetic sputtered atoms, but to a large number of nucleation sites which are formed by the bombard-ment of secondary electrons and/or high energetic neutral argon atoms during sputtering.
The energy distribution of output electrons (EDOE) from a channel electron multiplier was calculated theoretically for the unsaturated and the saturated operations. The theory is based on that of Yakobson on the gain characteristics of a channel electron multiplier. The theoretical result indicates that the half-width of EDOE under the unsaturated operation is larger than that under the saturated one. It is also found that the half-width depends on the field strength near the output of the channel. The experimental results are in good qualita-tive agreement with the theoretical results.
The rise of temperature of amorphous films of an As-Te-Ge system induced by Ar ion laser irradiation was measured by using various types of liquid crystals, and the change of optical transmission near the absorption edge by laser irradiation was compared with the corresponding change by thermal annealing. The results indicate that the change of optical properties in these amorphous films by laser irradiation may be ascribed to thermal effects.