EXISTENCE OF NON-UNIQUE STEADY STATE SOLUTIONS TO THE RMF CURRENT DRIVE EQUATIONS.

Abstract

It is shown that the value of the dc current driven in a plasma cylinder by means of a rotating magnetic field (RMF) is not unique for R/ delta APP GRTH 6 and eB omega /v//e//im approx. R/ delta , where R is the radius of the plasma cylinder, delta is the classical skin depth, v//e//i is the electron-ion momentum transfer collision frequency, B omega is the magnitude of the rotating magnetic field, e is the electron charge and m is the electron mass. This effect is predicted using three distinct approaches: (i) a steady state analysis which ignores the second and higher harmonics of the fields and currents; (ii) a qualitative model which utilizes the analogy between the RMF current drive technique and the operation of the induction motor; (iii) a solution of the initial boundary value equations describing the RMF current drive in cylindrical plasmas.