Plasma losses in high-current plasma configurations due to the ‘inverse skin effect’

Abstract

Experiments on zeta-pinches have shown that the surface layer of the plasma can be ejected towards the walls of the chamber. Phenomena of this type usually develop when the discharge current flowing through the circuit is decreasing, but they can also occur with a rising current when there is recurring discharge ignition.The application of an axial-magnetic field does not prevent the surface layer of the plasma from being ejected towards the chamber walls; it merely limits the rate at which the process occurs.It is shown that the break-up of the plasma sheath is due mainly to a reverse current induced in the surface layer of the pinch. When the discharge current is decreasing, a reverse current is produced by the ‘inverse skin effect’It is suggested that plasma losses due to the ‘inverse skin effect’ may also be observed for certain discharge regimes in theta-pinch, zeta, Tokamak and other systems.