Control of the motion of the ions in rotating magnetic field current drive: 1. Steady-state analysis

The equations describing current drive in an infinitely long plasma cylinder by means of two counter-rotating transverse magnetic fields are solved neglecting the second and higher harmonics. The existence of steady-state solutions where both rotating magnetic fields (RMFs) penetrate into the plasma much farther than the skin depth is verified. These steady-state solutions admit a special case where the RMFs are of equal frequency and magnitude, and can thus be implemented using an oscillating transverse magnetic field. The slip of the ion fluid with respect to the RMF is required to be extremely small (of order me/mi). The accessibility of these steady states from possible initial conditions is not investigated.