LINEAR-ANALYSIS OF A RESISTIVE COMPRESSIBLE PLASMA-FLOW AROUND A SHARP CORNER

In this article the authors describe a perturbation method used to calculate the flow of a compressible magnetized plasma around a sharp comer with a small turning angle. The main purpose for this analysis is the study of the flow in the exit region of a plasma accelerator in the regime of high magnetic Reynolds number. The physical model is based on a one-fluid resistive magnetohydrodynamic model (continuum model). The analysis predicts the existence of an acoustic expansion fan near the sharp corner, and a magnetoacoustic expansion fan in the far field. The current lines refract across the acoustic fan. Near an anode there is a strong mass depletion downstream of the comer. Along an anode, some of the current lines reattach far downstream, creating a magnetic boundary layer along the electrode. Near a cathode there is a region of high density and high temperature ahead of the comer. Along a cathode most of the current attaches itself ahead of the corner. Finally, the current refraction predicted by this theory correlates qualitatively with the experimental measurements in the regime of high magnetic Reynolds number.