Katsuhiko Horinouchi

A Method of Simulating Magnetically Driven Arcs

This paper presents a new, practical method of simulating the behavior of arcs driven by magnetic force in a gas. This simulation method is very useful in designing electric devices using magnetically driven arc technique. First, the authors describe the arc model. In this model, the arc is assumed to be a chain of small rigid cylindrical current elements. Each element receives Lorentz`s force from the magnetic field and a fluid drag force from the surrounding gas. Owing to the similarity between an arc and a rigid column, the drag force of the arc is expressed by that of the column. The element moves with the velocity determined by these forces. Consequently, the authors can obtain the behavior and the shape of the whole arc. Finally, simulation example is shown.

Two-dimensional observation of copper vapor in vacuum arcs by laser-induced fluorescence

The density distribution and the velocity of copper neutral atoms emitted from a single cathode spot in 40 A vacuum arc were measured by the two-dimensional (2-D) laser-induced fluorescence method. The density was calibrated from the two-dimensional fluorescence image observed by a CCD camera. The gap space was almost filled with the copper atoms, and the density reached 5/spl times/10/sup 19//m/sup 3/. We varied the wavelength of the laser light and measured the velocity of the copper atoms emitted from the cathode spot using the effect of Doppler shift. The velocity of the copper atoms was about 10 km/s.