Relaxation Model for Helicity Injection in Ohmic and Oscillating Current-Driven Reversed Field Pinch Discharges

Phys. Fluids 29, 1630 (91986)https://ireap.umd.edu/10.1063/1.8655041986Journal ArticlePlasma, Accelerator, and Nuclear Physics

A model for studying current drive by helicity injection in reversed field pinches (RFP’s) is proposed. In this model, the helicity supplied by the external circuits is injected into an exterior vacuum region that models the resistive edge region where skin currents can decay. Full Taylor relaxations allow this injected helicity to penetrate into the bulk of the plasma. Results on Ohmically driven discharges are shown, benchmarking the model with current experiments. Results on oscillating current drive are also presented, including studies of the dependence upon the driving voltages, the edge resistivity, and the number of relaxations per oscillation cycle.