Wake non-uniformity in MHD plasma

The effect of a wake-type nonuniformity on the effective plasma electrical conductivity and Hall parameter is investigated experimentally and theoretically. The nonuniformity is produced by a flat copper plate (vane) located in the supersonic nozzle that creates a two-dimensional wake in a plane parallel to the magnetic field vector. The vane removes approximately 1% of the channel thermal input, which results in a stagnation enthalpy defect in its wake of about 6%. Under these conditions, the optical and electrical diagnostics detect no conductivity defect. Its absence is confirmed by the generator performance, which remains the same with and without the vane. An approximate analytical model shows that the conductivity in the wake can, under certain conditions, be larger than that in the free stream.