Resistive magnetohydrodynamic transport model for a reversed field pinch. I. The model

摘要

A self-consistent transport model has been developed for an ohmically heated reversed field pinch (RFP). The model predicts, with no adjustable fitting parameters, the magnitude and radial dependence of the anomalous perpendicular thermal diffusivity as well as the macroscopic scaling relations for tau(E) and beta(p). Qualitatively, the model extends Taylor's theory of relaxation to driven systems with an external heating source, ohmic heating in the case of an RFP. The presence of such a heating source creates a finite nonzero pressure gradient in contrast to the zero pressure gradient predicted by Taylor's fully relaxed state. In the driven case, the magnitude of the pressure gradient is determined by assuming the pressure increases in magnitude and adjusts its shape until the entire profile is marginally stable to all resistive magnetohydrodynamic modes. This paper (paper I) of this two-paper sequence describes the development of the model and the numerical procedure for obtaining quantitative results. (C) 2003 American Institute of Physics. [References: 11]