Interdisciplinary Graduate School of Engineering Sciences, Kyushu University
Abstract
The necessary conditions for the formation of the uniform plasma sheet in gases (0.25-20 torr) are investigated using a device which simulates the initial breakdown and run down phases of the plasma focus. Under various experimental conditions, the structure and the development of the plasma sheet were observed by an image converter camera and diagnosed using a magnetic probe. As a result, the plasma sheet has been found to be filamentary in the region of a higher filling gas pressure and a lower storage energy, and to have a uniform structure in the region of a lower filling gas pressure and a higher storage energy. In addition, following points are found ; (1) when a uniform plasma sheet is formed, its propagation is described by a snowplow model, and (2) in order to form a uniform plasma sheet, there is a lower limit of the input energy density (input energy/particle)
