A plasma model for reversed field pinch circuit design

Abstract

A plasma model has been developed for use in the design of circuits for reversed field pinch (RFP) experiments. The magnetic field is assumed to evolve through a given series of relaxed states with the plasma resistivity specified as a function of time. At any instant the magnetic field configuration is determined by the field energy and the toroidal flux. If the Bessel function model (BFM) is chosen as the relaxed state then the magnetic helicity integral A.B d³x can be used as an alternative to the magnetic energy without altering the results. Simulations of discharges on ZETA and ETA BETA II are presented. By suitable choices of the relaxed field configuration and plasma resistivity it is possible to obtain close agreement with the experimental waveforms. Application to the proposed RFX device is discussed.