Development of a Simplified Plasma Opening Switch Using an Inverse Pinch as a Plasma Source

摘要

The design, development, and testing of the 'inverse pinch' plasma source for plasma opening switches is described. This source relies on the breakdown of a gas to form a plasma in an arrangement that is the inverse of a gas puff z-pinch. The plasma produced by the IP is best described as an expanding plasma ring and it has been designed to work with switches that have an IT product greater than I MA-micros. As a result, when using this source with a cylindrical POS, a single device mounted inside the center conductor is required as the ejected plasma matches the symmetry of the transmission line. The plasma produced by the IP was characterized on a test bed using framing photography, magnetic pick-up loops, spectroscopy, as well as single and dual beam heterodyne interferometry in various configurations. The results from field testing on the Hawk cylindrical POS with a shorted load is also reported. The POS experiments with a short circuit load indicated superior performance using a hydrogen plasma with strong dependence on the initial conditions. The data also implies that the conduction phase of the POS is influenced by secondary plasma formation from electrode surfaces. Further experimentation using the IP with H2 gas is planned.