A new method to produce an annular cylindrical plasma for imploding plasma experiments

Abstract

We present a new method to produce a hollow cylindrical metallic plasma. A metallic foil is exploded by discharging a capacitor bank; the vapor which is produced expands through an annular diaphragm and forms a cylindrical shell of weakly ionized gas, which can be imploded to produce a hot, dense plasma, resulting in a high-power soft x-ray pulse. The density of the hollow cylindrical plasma is measured by resonant interferometry, a new and powerful diagnostic for probing the plasma mass density before the compression (neutral density ≂1016 cm−3). Our device is complementary to supersonic gas-puff or exploding wires experiments.