IEEJ Transactions on Fundamentals and Materials
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
Volume 110 , Issue 10
Showing 1-17 articles out of 17 articles from the selected issue
  • Overview
    Masakiyo Matsumura
    1990 Volume 110 Issue 10 Pages 657-658
    Published: October 20, 1990
    Released: July 15, 2008
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  • Kaichi Fukuda, Nobuki Ibaraki
    1990 Volume 110 Issue 10 Pages 659-666
    Published: October 20, 1990
    Released: July 15, 2008
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  • Hiroshi Kanoh, Masakiyo Matsumura
    1990 Volume 110 Issue 10 Pages 667-669
    Published: October 20, 1990
    Released: July 15, 2008
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  • Nobutake Konishi, Kenji Miyata
    1990 Volume 110 Issue 10 Pages 670-674
    Published: October 20, 1990
    Released: July 15, 2008
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  • Tadashi Serikawa, Seiiti Shirai
    1990 Volume 110 Issue 10 Pages 675-678
    Published: October 20, 1990
    Released: July 15, 2008
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  • Setsuo Kaneko
    1990 Volume 110 Issue 10 Pages 679-683
    Published: October 20, 1990
    Released: July 15, 2008
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  • Koich Itagaki, Mortuza Ali, Hiroshi Kitamura, Takeo Maruyama
    1990 Volume 110 Issue 10 Pages 684-692
    Published: October 20, 1990
    Released: July 15, 2008
    JOURNAL FREE ACCESS
    Several sealed-off triggered vacuum gaps are connected in series to improve hold-off voltage. The characteristics of impulse breakdown voltage of these series connected gaps are investigated experimentally. The sum hold-off voltage of series connected gaps decrease to a unit hold-off voltage when the maximum value of voltage division ratio across the gaps increases to unity.
    Self breakdown probability of the series connected gaps is always higher than that of a single gap under the same conditions. Hence stage efficiency of the multi-stage gap decreases with increasing number of stages. Its value is 90% with 2-stage gap and 75% with 5-stage gap respectively under the same voltage division ratio and the same gap length (2.0mm) in each stage.
    Triggered breakdown voltage of 2 or 3-stage gap is several hundred volts when all gaps are simultaneously triggered at the peak of the main impulse wave and a working voltage range is nearly 100% in this case. The working voltage range decreases with number of stages. Its value is 45% with 3-stage gap and 15% with 5-stage gap respectively when one triggered gap is fired for switching.
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  • Kiyoji Kaneko, Shohachiro Nakanishi, Ryu-ichiro Ohyama, Yasushi Sugeno
    1990 Volume 110 Issue 10 Pages 693-698
    Published: October 20, 1990
    Released: July 15, 2008
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    The authors propose a new method for visual analysis of electric flux and equi-potential lines in two dimensional electrostatic fields. The method is derived from the study of an inversibility concerning with fluid flow mappers which are an equipment visualizing potential fields. The inversibility is based on a fact that equations interchanged roles of the stream-line and equipotential line equations in the theory of fluid dynamics can express the same fields by replacing the fluid flow conductivities with their inverse, which are corresponding to dielectric constants. In the fluid flow mapper simulating the fields by inversibility, the potential flow changes its direction at right angles for a regular use of fluid flow mappers. Moreover, in order to check the justification of this method, we apply the method to two dimensional fields of dielectric substances with the different dielectric constants. It is shown that the experimental results of the method agree with the numerical solutions by computer analysis and that the method is able to visualize both electric flux and equi-potential lines. Finally it is emphasized that the method presented in this paper can widely expand the ability of fluid flow mapper applications to electric field analysis.
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  • Hitoshi Okubo, Satoru Yanabu
    1990 Volume 110 Issue 10 Pages 699-706
    Published: October 20, 1990
    Released: July 15, 2008
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    This paper describes the development of three-dimensional electric field analysis by using so called segment method which enables to calculate the electric field with high accuracy and with enhanced efficiency, for high voltage apparatus.
    In the segment method, electrode configuration of high voltage apparatus is simulated by small components which are called as segments and by the arrangement of several kind of such segments.
    In this calculation, charge simulation method is used which is suitable for segment application. As basic segments, spherical, cylindrical and ring segments are used and in addition to these, as subsegments, disc and elbow segments are adopted for good simulation of the total electrode configuration.
    In this paper, fundamental construction and arrangement parameter of segments were discussed. Moreover the segment method were applied to an actual high voltage apparatus and the calculation accuracy was discussed. It was clarified that the segment method has enough calculation accuracy and is very efficient means for three-dimensional electric field analysis.
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  • Tadayoshi Miyata, Tsuyoshi Takeda, Toshihiko Kuwahara
    1990 Volume 110 Issue 10 Pages 707-714
    Published: October 20, 1990
    Released: July 15, 2008
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    The nature of two-dimensional electrostatic fields on the edges of anisotropic dielectric materials is discussed theoretically. To determine the validity of a numerical solution to a field problem related to compound anisotropic materials with sharp edges, it is necessary that physical properties and theoretical possibilities of the field be clarified. In this paper, the formula of the electric field and the eigenequation which describes the electric field near edges, where many anisotropic dielectric materials come into contact with each other, are introduced.
    Some examples of electric fields are given to show the potential distribution of the field, and it is proved that the two axces of anisotropy contribute separately to the each field distribution by every eigenvalue. The distribution of eigenvalues in wide variations of dielectric constants and the geometrical parameters of edges are investigated. In the result, a new phenomena which does not have any singular electric field (infinitly large field) even on the sharp edge was found.
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  • Koichiro Nakanishi, Hirotaka Muto, Haruhisa Fujii, Shigeo Sasaki, Susu ...
    1990 Volume 110 Issue 10 Pages 715-722
    Published: October 20, 1990
    Released: July 15, 2008
    JOURNAL FREE ACCESS
    Charge-up phenomena during ion implantation were studied using the wafers (1) covered with the 1μm thick photoresist and (2) fabricated with the MOS capacitor devices. The wafers were implanted with 35keV As+ at the beam currents of 1mA to 10mA. The surface potential was measured by a capacitive probe set in the chamber. The ion distribution was also measured by a beam profile monitor placed behind the rotating disc. Surface charging on the photoresist wafers in some cases led to the puncture of the resist layer. Probe measurement showed that the charge-up phenomena were to a large extent governed by the behavior of the secondary electrons generated at ion implantation. The wafers with the MOS devices hardly failed by the charge build-up because of the bulk conduction through the thin oxide. However, the C-V measurement indicated that the deterioration of the oxide are influenced by the beam distribution.
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  • Ko Agatsuma
    1990 Volume 110 Issue 10 Pages 723-728
    Published: October 20, 1990
    Released: July 15, 2008
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    A numerical analysis of stability and thermal performance of internally cooled superconductors has been investigated. An analysis of this system has been performed using one dimensional computer code developed by Arp(1) based on a program for non-linear partially differential equations by Sinovec(2) and slightly modified by the author. The effects of helium mass flow rate and also hydraulic perimeter upon the stability margin has been studied. The computer simulation results will be presented. These results of computer analysis indicate that the thermally induced pressure gradients and fluid velocity caused by rapid perturbations are responsible for the stability margin, and both of mass flow rate and hydraulic perimeter are quite significant for high stability margins. A dual composite cooling channeled forced flow cooled superconductor will be suggested from these results.
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  • Masaaki Ohshima, Akihiko Yoshida, Akira Kobayashi, Hiromochi Tsuji
    1990 Volume 110 Issue 10 Pages 729-738
    Published: October 20, 1990
    Released: July 15, 2008
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    β"-Aluminas which transmit sodium ions and do not conduct electrons are expected to be practically applied for solid electrolytes and separators in sodium-sulfur batteries. It is known that large sodium-ion current density fractures β"-Aluminas instantly. For making this fracture mechanism clear, the temperature and thermal stress distribution in β"-Alumina occurred by transmitting sodium ions were calculated. Then using β"-Alumina tubes, experiments in which they were cracked by large current density were carried out. The values of thermal stress at these experiments were solved using upper calculation. These values were almost equal to those of β"-Aluminas' mechanical strength. The fracture mechanism of β"-Aluminas by transmitting large sodium-ion current density is supposed to be thermal stress occured by Joules' loss in β"-Aluminas.
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  • Morinobu Endo, Katsumi Miyashita, Kouichi Atsumi
    1990 Volume 110 Issue 10 Pages 739-746
    Published: October 20, 1990
    Released: July 15, 2008
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    Bi-system Hi-Tc ceramics (BSCCO-system) with Pb additive have been obtained by sintering in air or in Ar atmosphere containing low pressure of oxygen, at temperatures 830-860°C. The relationships between the superconductive properties and the texture have been studied. By adding the suitable amount of Pb to BSCCO-system, the voiume fraction of 110K-Tc superconductive phase increases, but the density of the samples becomes lower by expansion. Observation by scanning and high resolution transmission electoron microscope, it is shown that the samples which contain 110K -Tc phase consist of plate-like particles with lattice defects. Furthermore, the samples sintered at around melting point then followed by normal sintering condition exhibit 50% larger critical current Jc and smaller decrease in Jc under magnetic field than those of normaly sintered ones, at liq. N2 temperature. Jc decreases drastically with magnetic field applied, and also changes with the direction of themagnetic field. AC voltage and current wave forms of the ceramics under superconduction state are measured by changing the frequency up to 1kHz, and discussed in comparison with DC property.
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  • Kaoru Ohya, Ichiro Mori
    1990 Volume 110 Issue 10 Pages 747-748
    Published: October 20, 1990
    Released: July 15, 2008
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  • Kiyoji Kaneko, Ryu-ichiro Ohyama, Yasushi Sugeno
    1990 Volume 110 Issue 10 Pages 749-750
    Published: October 20, 1990
    Released: July 15, 2008
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  • Yukiya Hirashima
    1990 Volume 110 Issue 10 Pages 751-752
    Published: October 20, 1990
    Released: July 15, 2008
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