Initial results of parallel-plate plasma opening switch experiments on HAWK

Summary form only given. Results of parallel-plate plasma opening switch (POS) experiments on HAWK are presented. The Hawk generator produces a sinusoidal output current of amplitude /spl sim/750 kA and quarter period /spl sim/1.2 its. The POS used is a tri-plate with a single cathode and two anode plates, each 15 cm wide. The plasma is injected from plasma guns through slots in the anodes. This POS performs almost as well as a comparable coaxial POS for short-circuit load shots with conduction times less than 700 ns. The parallel plate geometry provides much better diagnostic access than the standard coaxial POS. Framing camera images of the plasma imply that the current snowplows until it reaches the end of the injected plasma and opens near the cathode. A two-color laser interferometer is used to measure the electron and neutral densities of the plasma in the switch and in the magnetically insulated transmission line (MITL) between the switch and load integrated along chords in the /spl theta/-like direction. The electron density measured in the injected plasma region rises sharply during conduction and falls rapidly near the time of opening consistent with a snowplow traveling through the injection region.