Steady Current Generation by RF Travelling Field in a Magnetized Toroidal Plasma

Abstract

There are two factors to control the currents driven by RF fields travelling along a toroidal plasma; one is the penetration depth of the RF magnetic field into the plasma, and the other is the ratio of the RF magnetic field to the static toroidal magnetic field B _t . The currents are observed to increase with B _t , since the skin depth for the RF fields increases. There is optimum toroidal magnetic field to hold a maximum toroidal current, and at higher B _t , the toroidal currents decrease as more strongly than B _t ^-1 . The toroidal current can also be excited by a local assembly of RF coils.