Expansion of a Resistive Spherical Plasma in a Magnetic Field

The expansion of a resistive plasma into an external magnetic field has been treated in the limit in which the magnetic field does not perturb the plasma motion. The use of a class of exact solutions for the purely radial motion of the plasma in the absence of a field permits the reduction of the electromagnetic problem to consideration of a diffusion equation for the magnetic stream function. Explicit solutions are derived for a resistive spherical plasma expanding into a uniform applied magnetic field. Representative numerical results related to laser-produced plasma experiments of Haught and Polk are presented.