Expansion and Thermalization of Plasma in a Non-Uniform Magnetic Channel

Theoretical investigations of the unsteady motion of plasma in a magnetic channel are made on the basis of the hydromagnetic theory of an ideal fluid. A set of one dimensional equations on which the investigations are made is derived in the near-axis approximation from three dimensional equations. Using these equations dynamical expansion of an initially uniform plasma at rest contained in a region of strong magnetic field into a region of weaker field, and shock thermalization of the expanding plasma on colliding with a rigid wall (or with another flow in the opposite direction) or being decelerated by a magnetic barrier are investigated. Analyses are made both analytically and numerically.