Characterization of plasma flow through magnetic nozzles

An account of research undertaken to describe the steady, axisymmetric flow of plasmas through rocket nozzles, with attention directed to the use of magnetic fields for guiding or propelling the plasmas is reported. The primary emphasis is on simply connected nozzles containing strictly longitudinal (B sub r, O, B sub z) magnetic fields to guide the plasma, with secondary consideration given to annular nozzles containing strictly azimuthal (O, B sub theta, O) magnetic fields to propel the plasma. The possibility and desirability of using hot plasmas in a repetitive mode is discussed, and motivates our consideration of an extensive range of parameters. Although slightly ionized gases having low temperatures (a fracture of an eV) and low magnetic Reynolds numbers often are the objects of valid and useful research (for example, in connection with MHD generators, with MPD thrusters, and with arc heaters to provide sources of hot gas for expanding gas-dynamic flow fields), the focus is upon the effective and efficient interaction of substantial plasmas with guiding or driving magnetic fields. Thus, focus is primarily on highly ionized plasmas that are not dominated by resistive dissipation. Some of the principal physics issues associated with these concepts are addressed.