Halo plasma physics model for mirror machines with neutral beam injection

A model for halo plasmas in mirror machines sustained by neutral beam injection is described and applied to the conceptual tandem mirror test facilities TDF and TASKA-M. Halo source terms include alpha particle heating, radial transport, neutral beam attenuation, and reionization of charge exchanged neutrals. The primary sinks are end loss and charge exchange. The neutral beams are found to contribute substantially to first wall surface heat load, but little to halo density or temperature. Reference halo parameters for TDF and TASKA-M are exhibited. (author)