Numerical and theoretical developments in plasma erosion opening switch research

Summary form only given, as follows. The plasma erosion opening switch (PEOS) can conduct megaampere levels of current for 50 ns to 1 mu s before opening into a load. The opening times can be a factor of ten times smaller than the conduction times. It has been observed experimentally that the switch does not open until the magnetic field and current penetrate through to the load end of the plasma, and that current is spread almost uniformly in a broad channel behind the current front. Theoretical analyses of the PEOS have been carried out to understand the physical mechanisms behind the current penetration, conduction, and switch opening processes. Particle-in-cell, fluid, and magnetohydrodynamic simulations, as well as analytic means, have been compared to experimental results. These methods have shown the important roles played by boundary conditions and emission models, electrostatic potentials that develop in the plasma, anomalous resistivity, and magnetic insulation and gap formation near the cathode. In the long-conduction-time switch, the effects of J*B acceleration of the plasma are more important than in the short-conduction-time switch and have been given special consideration. Simulations have been run with and without additional modeling for anomalous collisions. In the former case, broader current channels and linear conduction current sealing with density and switch length are observed, bringing collisional simulation results in closer agreement with experimental data.<>