A simulation code for calculating a population inversion in an exploding Cu-wire plasma has been developed. Time variations of the radial distribution of the plasma density and temperature, the current, and the voltage are calculated from the code. The current and voltage wave forms and the temporal population inversion profile are in reasonably good agreement with corresponding experimental results. The dependence of the population inversion on a distance from the center of the plasma and on the charging voltage is shown. The excitation mechanism in the exploding Cu-wire plasma is also discussed.

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Solving the inverse problem of obtaining field sources can be classified into following two methods. The first method consists of obtaining unique solution by imposing a certain constraint on the governing equation of the inverse problem. This is because an infinite number of possible solutions can satisfy the governing equation. In other words, the same local field can be generated by different field source distributions. The second method carries out examination of all the possible solutions, and their weight evaluation. The sampled pattern matching (SPM) method belongs to this method, while the minimum-norm method represents the former method. In this paper, comparison between the SPM and minimum-norm methods is carried out. As a result, it is clarified that the SPM method is superior to the minimum-norm method when the field source is distributed in the direction normal to a field measurement surface. Finally, a faster SPM method is proposed in order to realize a real-time analysis of the inverse problem. The validity of the faster SPM method is verified by experiments.

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A voltage-current characteristic model of a low pressure discharge tube is developed for analyzing the properties of a high-frequency operation circuit. The model is derived using the continuity equation for electrons and the electron mobility as a function of the electron temperature. The obtained voltage-current (V-i) relation is as follows:
V{KvO3+(1/Im)(dIm/dt)/Q1+KvQ2Im}(i/Im)1/Kf
The constants in the formula are determined from the discharge waveforms measured under the standard condition. Using the developed model, voltage waveforms are calculated for several cases. The agreement between the calculation and the measurement is good enough for analyzing the high-frequency operation circuit-properties. The model can apply not only to the high-frequency operation but also to the case of the discharge current modulated by a low-frequency component.

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On the surface of thermal control materials of artificial satellites, the surface discharge occasionally occurs especially on high-altitude orbits. In this paper, emitted light of discharge and outgases in a vacuum chamber are measured to investigate this phenomenon. Samples used for experiments are fluoroethylenepropylene (FEP) and polyethyleneterephthalate (PET) films of 25μm and 127μm thick.
The released gas from a specimen under irradiation of electron beam increases the pressure around the specimen. The mass spectrum of gas released from the specimens by the discharge shows that water molecules in the chamber diminish after discharges on PET of both thicknesses and 25μm FEP. It is probable that water molecules are involved in these discharges. The spectrum analyses of emitted light show that at the initial period of a discharge the light emitted from hydrogen atom (Hα) prevails.
Comparing FEP and PET, FEP releases less amount of gas after the occurrence of a discharge. Therefore, the concentration of discharge energy might be lower. Especially in case of the surface discharge on 127μm thick FEP, the small change of the proportion of the light from hydrogen and the small diminution of water coincides.

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In this paper we dicuss the effect of stress on the magnetization change under constant magnetic field for amorphous soft magnetic ribbons, which have positive or negative signs of magnetostriction constants.
Two kinds of magnetization change can be defined from the stress magnetization curve, that is, reversible magnetization change and irreversible magnetization change. The locus of magnetization change of amor-phous ribbon due to stress was first shown by us.
It is convinient to use amorphous ribbon material to discuss the effect of stress on magnetic materials because of absence of magnetocrystalline anisotropy. We discussed the mechanism of the two effects from the results of the observation of domain structures.
It is concluded that the deformations or displacement of 180 degree domain walls are responsible for the occurrence of the irreversible magnetization change, while the reversible rotation of magnetization vectors due to application of stress can be deduced to the origin of the reversible magnetization change.

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Pt/Co multilayer thin films were prepared on Si substrates by vacuum evaporation in connection with the thermal stability of Pt/Co multilayers as magneto-optical recording media. In order to avoid the growth of CoPt compound alloyed by the interdiffusion of both metals at elevated temperature, thin blocking layers were introduced at the interface between Pt and Co films. The blocking layers were metal nitrides and were prepared on the lower metal layer by exposing in nitrogen at 200°C before the deposition of upper layer. On the multilayer films with the blocking layer, the degradation of magnetic properties such as Hc and Is was not observed after the heating test until 400°C.

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Radical reactions on tellurium surface are studied to give an insight into the growth mechanism of a telluriumcarbon (Te-C) film which has been employed as an optical recording layer. Ions and radicals in a methane/argon rf plasma are selectively extracted through an orifice and a mass filter into a surface-reaction chamber where they impinge on a clean tellurium target. Quadrupole-mass analysis of reaction products revealed formation of volatile tellurium compounds: (1) hydrogen telluride TeH₂ formed by atomic hydrogen, H₂ and CH₄ and (2) dimethyl tellurium Te (CH₃)₂ formed by methyl radical CH₃. The deposition processes of Te-C films by conventional magnetron sputtering are discussed.

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Rubber insulating gloves for electrical working must always keep dielectric properties in good condition in order to prevent a line man from electric shock. However, they are deteriorated by various stresses to which they are subjected in service and keeping. Therefore, their dielectric deterioration and estimation of lifetime were studied when they were actually used in high voltage electrical working on pole of distribution lines, because such a place is considered where the frequency of use is large and the environment is severe. As the result, it was found that the usable lifetime was considerably shorter than expected because of their mechanical damages in service. Also, measured dielectric and mechanical properties showed deterioration tendencies on the whole, though their data scattered on a wide range. And the voltage endurance lifetime was estimated for the used days with the help of statistical treatment, and it was confirmed that there are cases where a few used gloves fail in the voltage proof test of 10kV even if they once passed in the withstand test of 20kV when they were new products. Furthermore, it was also shown that the electrical breakdown point was not decided by innumerable slight scratches caused in service.

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