A numerical study of rotating magnetic fields as a current drive for field reversed configurations

A fixed ion model has been developed to study the use of a Rotating Magnetic Field (RMF) as a current drive mechanism in a Field Reversed Configuration (FRC). This model is used to investigate the physics of RMF current drive in a parameter range of interest to two experiments at the University of Washington. Empirical expressions are found to characterize the critical RMF magnitude required for full penetration and the rate of RMF penetration. It is shown that in the presence of a strong anisotropic plasma resistivity, the direction and magnitude of the axial bias field can have a strong influence on the penetration of an RMF. Calculations that include the effects of realistic RMF antennae at finite radius are used to find the effects of coil spacing and positioning. (C) 1999 American Institute of Physics. [S1070-664X(99)01507-4].