Study of the breakdown phase in a pseudospark switch. II. Ultrafast CCD cameragrams using He+ spectral line emission

For pt.I see ibid., vol.23, p.362 (1995) In a companion paper, a model was developed to describe the breakdown of a pseudospark switch. This model shows the control of the current by its own magnetic field. The computed results matched the experimental current and voltage traces, but the model was oversimplified regarding the actual flux lines of current and magnetic field. In this paper, the magnetic pressure effect is considered together with the location of bright spots on the back faces of the electrodes. These facts suggest a twisted arrangement of the I and B flux lines to reduce the Laplace forces. Furthermore, the development of the “superdense glow discharge” was observed by way of a high resolution CCD camera operating within the spectral line of the positive ions in helium. High definition frames were obtained with an exposure time of 3 ns. Some details in these pictures seem to support the proposed configuration