Ryozo Ishibashi

High Frequency Characteristics of Impedances to Ground And Field Distributions of Ground Electrodes

High frequency characteristics of impedances to ground and field distributions of ground electrodes are calculated by the current simulation method together with the method of images. Numerical calculations concerning some typical electrodes are shown. An expression for approximating impedances to ground from corresponding dc resistances is proposed and errors are estimated.

Calculation of Complex Fields in Conducting Media

A method for calculating complex fields between lec electrods in conducting media is proposed. It is shown that there exist dual relationships between a complex field due to an alternating current source in a conducting medium and an electrostatic field due to a charge in a dielectric medium. If a solution to the problem of an electrostatic field is known, then the solution to the corresponding problem of a complex field is easily bobtained on the basis of the above dual relationships. Numerical calculations and experiments were carried out to verify the proposed method.

I-V characteristics and liquid motion in needle-to-plane and razor blade-to-plane configurations in transformer oil and liquid nitrogen

Current-voltage (I-V) characteristics are measured in a negative needle-to-plane configuration and a negative razor blade-to-plane configuration in transformer oil and liquid nitrogen. Linear pots of V vs. I/sup 1/2/ in the former configuration of V vs. I/sup 1/3/ in the latter configuration are obtained respectively in the space-charge limitation (SCL). The liquid motions in the above two configurations in SCL are computed respectively from both the Navier-Stokes equation and the continuity equation by the finite-difference method. From the experimental and computational results of the liquid motions, the relations between V and I in two configurations are derived, respectively. >

Electric Fields in Dielectric Multi-Layers Calculated by Digital Computer

The electric field of a point charge or a spherical conductor in three or more dielectric layers on a plane conductor is calculated ated by digital computer. That of a point charge is calculated by the method of images, and that of a spherical conductor by the charge simulation method in combination with the method of images. Numerical examples show that the potential, the field strength, and the flux density, all satisfy the boundary conditions with good accuracy. The method can be applied to fields of a line charge, a pillar conductor, and an electrode of body of revolution in the same circumstance.

High-Field Electronic Conduction in Liquid Nitrogen

Conduction characteristics between a needle and a plane electrode in liquid nitrogen (LN2) were investigated when a negative dc voltage was applied to the needle. Both characteristics, the overall time of voltage application T vs current I and the applied voltage V vs current I, showed the onset currents at specific values of applied voltage. On the other hand, it was found that positive triboelectric charge was produced when LN2 was forced through a metal pipe from a Dewar into a cryostat. By applying the Fowler-Nordheim theory, we showed that electron emission from a cathode was greatly influenced by both the layer of positive ions and microscopic projections on the cathode surface. Parameters in the theory concerning the emission of electrons from the cathode have not been made clear, but in this paper, they were investigated and numerically determined.

Electric Fields Due to a Point or a Line Charge in Two Dielectric Layers on a Conducting Plane

Electric fields due to a point charge located in two dielectric layers on a conducting plane are sought. By an extensive application of the theory of images, the fields are expressed accurately in the form of infinite series of image charges. The series are convergent and the fields may be calculated. In the case of a line charge, the same expressions as in point one are presented.