Three Fluid Hall MHD Simulations of a High Density Plasma Opening Switch

Two ion species plasma opening switch (POS) simulations are studied computationally and compared with experiment [1]. The Hall parameter H, the ratio of ion skin depth to system size, is of order unity. The ion species are protons and carbon, with electrons maintaining quasineutality. The velocities of the ion species are combined into average and difference velocities. The average velocity satisfies the usual MHD equation with a modified inertial term. In the low H limit, the difference velocity is a drift in the direction of the current, in which light and heavy ions move in different directions. The simulations account for the two main experimental observations. First, the experimental evolution is not strongly dependent on the polarity of the magnetic field, as in a low density, high H POS. Second, light and heavy ions tend to move apart. Three fluid Hall equations are being developed with a three dimensional magnetic field, depending on two spatial directions. The 2 1/2D equations will be applied to reconnection studies. [1] A. Arad et al. Phys. Plasmas 10, 112 (2003)