Single and multiple wire Z-pinch experiments on marx-driven water-line pulser

Summary form only given. Wire Z-pinch experiments are underway on a new Marx-bank driven, water-line pulser with 40-50 kA peak current and 130 ns risetime. Previous, lower current wire explosion experiments were performed to investigate the effects of wire morphology on plasma instabilities in copper wires. In the copper studies, laser-shadowgraphy of DC preheated wires showed more rapid expansion and increased development of lateral striations in the plasma column. These striations had growth rates corresponding to Rayleigh-Taylor. Causes of this effect possibly include: the growth of lateral grain boundaries in the wire material due to the DC preheating, or increased energy deposition in the cleaner wires (by reduction of parasitic current in impurity corona). Wire heating experiments repeated on tungsten wires at higher currents will determine if striations similar to those seen in copper can be reproduced and, if so, whether the effect is due to grain structure or to greater energy deposition. Besides DC preheating, investigations into wire-corona breakdown, energy deposition, and the interaction of multiple wires are under investigation. Diagnostics on the experiment include laser-shadowgraphy, PIN diodes, and optical spectroscopy. Future experiments will employ a 1 MA linear transformer driver (LTD), under construction