A Model of Energy Balance in a Plasma Dominated by the MHD Relaxation Process.

Abstract

Recent experiments into the ULQ (ultra low q) regime of toroidal discharges found a significant level of resistance anomaly, which enhances the inductive power influx even in a higher electron temperature regime, and a part of the excess of the energy input goes directly into ions, resulting in anomalous ion heating. The relaxation process simultaneously affects the electron energy confinement because of pertubed magnetic fields. Simple zero-dimensional energy balance equations have been studied with modeling the resistance anomaly, direct ion heating and associated enhanced energy loss self-consistently. The ion heating mechanism is based on a viscous dissipation of fluctuations in the relaxation process. There is a possibility of applying a turbulent plasma to ion heating in start-up phase of a tokamak reactor.