The structure of self-field accelerated plasma flows

An analysis is presented of self-field accelerated quasi-one-dimensional plasma flows with zero axial current. The dominance of magnetic convection over diffusion leads to the formation of inlet and exit concentration layers which are analyzed by asymptotic matching. The sonic passage condition is found to control injector conditions, but not channel voltage. Throats are shown to be approximately magnetosonic. Performance factors accounting for inlet convergence and nozzle divergence are derived by exploiting the smallness of pressure forces. The effect of finite magnetic Reynolds numbers is seen to be moderate down to Rm of about 3 for contoured channels, but to Rm of about 10 for constant-area channels. Contouring is shown to be effective for control of current and dissipation concentrations.