Boundary conditions for use in plasma simulations

Summary form only given, as follows. Boundary conditions are presented for use in magnetohydrodynamic, particle-in-cell, and multi-fluid computer programs. The boundary conditions consist of velocity moments for three plasma species near a plasma-facing surface. The three plasma species are plasma ions, plasma electrons and surface emitted electrons. The boundary conditions are developed using a fully kinetic theoretical description of the plasma sheath which takes into account space-charge saturated electron emission from a plasma-facing surface. It is necessary to take into account space-charge saturated electron emission from the plasma-facing surface because of a recent finding which indicates that most of the commonly-used plasma-facing surface materials can reach secondary electron emission coefficients large enough for the emission to be space-charge limited. The boundary conditions are in terms of sheath and presheath potential drops and simple expressions (which are fits to numerical results) are provided for these potential drops.