Magnetic Field Penetration in Axially Symmetric High-Current Plasma Systems

This article analyzes the transport of a magnetic field in axisymmetric plasma systems using simple formulas derived for its velocity in collisionless and collisional plasmas. The analysis shows that the magnetic field velocity in both cases is determined by the magnetic field rise rate to plasma density ratio raised to the power of 1/2. As the plasma density increases, the field velocity starts to depend on the plasma aggregation by a magnetic piston. Because the electron flow velocity in any case is limited by the axial drift velocity in crossed magnetic and polarization electric fields, the current channel conductivity is suppressed with respect to the Spitzer value by a factor equal to the magnetization parameter raised to one or another power.