A long conduction time compact torus plasma flow switch

Experiments to form and accelerate compact toroid (CT) plasmas have been performed on the 9.4 MJ Shiva Star fast capacitor bank at Phillips Laboratory since late 1990. We investigate the possibility of employing a CT as a very fast opening switch by performing 2-1/2 dimensional magnetohydrodynamic computer simulations of a pair of axisymmetric, albeit geometrically-complex, switch designs. Both designs conduct current for ten or more μs. The first design relies on the acceleration of the CT to high speed whereas the second design does not. Although both designs hold promise for achieving a fast (less than 100 ns) opening time, the second may prove to be a preferred design because of its low impedance.