Radiographic Investigation of Metal-Puff Plasma Jets Generated by Vacuum Arcs

Abstract

The structure of the plasma jet of a vacuum arc discharge was investigated using different experimental arrangements for jet formation. To examine the external shape and internal structure of the plasma jet, optical imaging and pulsed X-ray radiography were used. The latter is the most informative method for investigating the density distribution in a dense plasma jet. This diagnostic, combined with a step wedge, provides a way of analyzing quantitatively the plasma jet structure. As the X-ray source for radiography, an X-pinch was used. The measured surface density of an aluminum plasma jet ranged up to 340 μg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The arc discharge current and the plasma jet current were measured with Rogowski coils. The experiment has shown that in the case of a plasma gun with return current posts; a pinch effect arises which provides for the formation of a confined plasma jet.