A Investigation of Oscillating Field Current Drive (ofcd) in a Reversed Field Pinch.

After a brief review of the history and the recent developments of Oscillating Field Current Drive (OFCD), a lambda profile for the modified Bessel function model is suggested and a 0-D simulation equation based on helicity balance is derived. Implications of the relaxation effect for the experimental results of OFCD are considered. Based on the nonlinear relation between the injected helicity and the driven toroidal current, current saturation effects are investigated for various field models. A method for using OFCD as a tool to study plasma properties is discussed, and as an example the resistivity profile is considered. The sensitivity of this method to model assumptions is examined.