A Boundary Condition for Comlputational Magnetohydrohynamics

A new "background plasma" method for treating boundaries in Eulerian magnetohydrodynamic computations is presented. Previously unconsidered aspects of plasma confinement by a wall are examined in the formulation of the boundary condition. Innovations include a distinct condition under which a plasma can separate from a wall resulting in an influx of "background plasma," the use of boundary values which are interpreted to be interface values not included in volume integrations, and a condition under which a plasma returns to the wall resulting in a stoppage of the outflux of "background plasma." Excellent agreement is obtained between a Lagrangian computation and an Eulerian computation incorporating the new boundary condition.