Numerical MHD simulations of the DECADE plasma opening switch using MACH2

Summary form only given. Numerical simulations of the DECADE opening switch have been performed using the MHD code MACH2. This code has multiblock grid capability which makes it possible to simulate the detailed geometry of the actual switch configuration. Modifications were made to MACH2 to permit input of time dependent density and velocity of the initial injection plasma based on experimental measurements of these quantities. The code was also modified to permit a determination of the inductive component of switch voltage when using a non-flowing upstream boundary condition. The simulations have shown that the plasma flow and magnetic field evolution in the switch is a strong function of the initial plasma density distribution. Opening of the switch was simulated by use of an artificially large resistive diffusion. At the approach of opening time in the switch, the Hall parameter becomes large, and the Hall effect may play an important role in opening behavior. An effort is underway to add new numerical algorithms to MACH2 which will permit inclusion of the Hall effect in the simulation.