InSb thin films were prepared on mica substrates by conventional vacuum evaporation with suitable temperature programming for source and substrate, and their electrical properties were investigated. Though the deposited films had InSb-In structure due to the loss of antimony during evaporation, the films prepared by zone refined InSb source material with lower deposition rate obtained p-type conduction. The films showed dendritic crystal regrowth, and obtained high mobilities of electron and hole respectively. The acceptor impurities were the residual impurities originally included in In and Sb source materials which had high segregation constants during the zone refining process. The p-InSb films showed n-type conduction at room temperature range, and the high electron mobility was available for many practical devices.

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Space charge in full size ±250kV DC cables was measured using the pulse-electroacoustic method. Two types of newly developed DC XLPE cables with 20mm thick insulation were subjected to the measurement under the DC voltage of 500kV keeping the conductor temperature both at the room temperature and at 85°C. Both qualitative analysis on the space charge distribution and the quantitative analysis on the electric fields in the vicinity of semicon interfaces were done. It was shown that the field in the vicinity of the inner semicon tends to increase by 10-40% when the polarity of the applied voltage was switched, in the case when the conductor was kept at 85°C. However, the distortion of the electric field was significantly small compared to that expected with conventional XLPE cables. As the result, the subjected DC cables are considered to have stable DC characteristics from the viewpoint of space charge behavior.

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We have analyzed the pulsed electric field of a high-speed framing camera with the proximity focused image intensifier (PFII) using the three-dimensional finite-difference time-domain (FD-TD) method. When the temporal resolution of sub-nanosecond is required for a high-speed camera, the non-uniform propagation of the gating pulse over the electrode degrades the quality of the image, as has been reported experimentally by one of the authors. The present calculation successfully simulated such a degradation when a circular electrode ahead of the photocathode was divided into two electrically independent semicircles. The reason for this degradation has been attributed so far to the unwanted propagation, or leakage, of field around a guard electrode that divides the circular electrode. We have found, however, that this is not the case, and that this is due to the leakage electric field propagates through the space between the photocathode and the electrodes. Certain methods to resolve this problem have been suggested.

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Photoabsorption current is measured under vacuum ultraviolet irradiation between wavelength range of 170nm to 110nm. The current is appreciable at the wavelength of shorter than 160nm. The current increases at 132nm that is the ionization wavelength of NO gas and further increase of the current arises at 127nm that is the dissociation wavelength of N₂.
From the facts of above mentioned and the other experimental results, photoionization and photoabsorption processes of the air are discussed here with attention to behavior of N₂ and O₂ that are the principal ingredient of the air.
As a result, main processes of photoionization of the air are supposed as follows. N₂ is dissociated to N by absorption and N is oxidized to NO. Then, NO is ionized by vacuum ultraviolet. It is found that the ionization process of created NO is mainly single-photon process but multiphoton process is negligible in this case.

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In order to improve the long-term reliability of XLPE cables, it is essential to understand the mechanism of deterioration and breakdown as a result of long-term voltage application.
This paper presents the results of our study on the deterioration mechanism of polyethylene, which is the insulating material of XLPE cables, focusing mainly on the electrical deterioration luminescence phenomenon observed using model samples that simulate the regions of high electric field enhancement, e.g., impurities and protrusions. A report is also given on an evaluation of the long-life characteristics of the insulating material, based on electrical deterioration luminescence measurements that take into account the above deterioration mechanism.

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HDPE has excellent insulating properties under DC voltage in sheet sample, since its breakdown strength is high and the space charge accumulation is small. However, thickness dependence of DC breakdown strength was observed in HDPE cable, which was considered to be caused by the increase of voids with the increase in cable wall thickness. DC breakdown seems not to occur due to void discharge deterioration. It was considered that the void discharge in HDPE cable insulation where the space charges are accumulated under high DC stress, induces electron avalanche and lead to breakdown.

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Complex conductivity of superconductor (CCS) is a principal parameter in the case of estimation for surface impedance of superconductor. Usual investigation on CCS is based on two fluid model, which is constructed on the assumption that electron pair has not collission with phonon. However, real part of CCS that derived from above two fluid model are not agree with measured values. We formulate modified two fluid model provided that moving electron pair has characteristic of equivalent loss which depend on high frequency electric field, and both density of super and normal electron are related by Rate equation. Furthermore, CCS is formulated by using modified two fluid model. Finally, numerical results of real part of CCS which obtained by modified two fluid model are agree with measured values.

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The sound absorption coefficients of powder beds comprised of fine powders (white carbon and vermiculite) were determined using a reverberation room. The characteristic curves of the powder beds showed high peaks in the low-frequency range, due to the excitation of longitudinal vibration modes in the powder beds by random incident sound. Multi-layered constructions composed of the powder layers and porous sound-absorbing materials (polyurethane foam sheets) were designed, and their sound absorption properties were investigated. Measurements showed that the multi-layered constructions have high sound absorption peaks in the low-frequency range, which are considered to be due to the combined effects of powder vibration and viscous dissipation in the pores of the polyurethane foam. The combination of two materials possessing different sound absorption characteristics results in an expansion of the sound absorption frequency range and indicates the possibility of a new sound absorbing material for low-frequency sound.
Sound absorption simulation based on electric transmission line theory was applied to the multi-layered constructions. The calculated results agreed well with the measured results. It was found that a simulation using the propagation constant and characteristic impedance of the constituent materials is useful in designing the frequency characteristics of these constructions.

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It has been understood that the deterioration of electrical properties was caused by the amount of dissolved water in liquid dielectrics. Moreover, it is believed that such dissolved water molecules diffuse into free space in liquid dielectrics uniformly, because the behavior of water molecule can not be observed by Karlfisher's method, though only the amount of water has been observed. But recently, by using FT-IR method, it is published that the almost dissolved water molecules behave as binding water bound by the polar bases of dielectrics. The binding force was caused by hydrogen bonds between the water and dielectric molecules. In this paper, the relation between the conductivity and the binding force is considered by calculating the hydrogen bonding energy among the molecules. As the result, it is seen that the conductivity of hydrated dielectrics can be determined by the strength of hydrogen bonding energy and the amount of water, and experimental equation for conductivity is derived from this relations.

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SiO₂ films were prepared by plasma enhanced chemical vapor deposition (PECVD) using tetraethoxysilane (TEOS) and N₂O. The Si-OH concentrations in the films deposited at a low temperature (200°C) was found to be below the detection limit of Fourier transform infrared spectroscopy (FTIR) with the RF Power more than 80W. Optical emission spectroscopic study for SiO₂ deposition process in gas phase showed that emission intensities of both atomic oxygen and atomic hydrogen depended strongly on RF power. Further mass spectrometric study in N₂O plasma indicated that atomic oxygen increased with RF power due to decomposition of N₂O in N₂ and O. In addition, we tried to prepare SiO₂ films using TEOS and He in order to study the role of oxidant. It was found that low impurity SiO₂ films can be obtained at temperarure lower than 200°C with higher RF power through the effects of oxidation by atomic oxygen and electron impact decomposition.

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p-Type doping in ZnSe is one of the important research subject to realize blue lasers. Capacitance- voltage (C-V) measurements are frequently used to characterize grown p-ZnSe. However, there remains a problem in C-V measurements where measured capacitances decrease with measurement frequencies. In this paper, this problem was studies with a realistic equivalent circuit. Our main findings are following: For low-doped samples that have low leakage current, the depletion layer capacitance is accurately measured at frequencies lower than 10kHz considering electrode geometry. For high-doped samples that have higher leakage current, the depletion layer capacitance is usually underestimated and our analysis is necessary to accurately estimate the net acceptor concentration. The net acceptor concentration of-1×10¹⁷cm^-3 was realized in p-ZnSe grown by MOMBE.

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