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Stepped pressure equilibrium with relaxed flow and applications in reversed-field pinch plasmas
- Publication Year :
- 2020
- Publisher :
- arXiv, 2020.
-
Abstract
- The Multi-region Relaxed MHD (MRxMHD) has been successful in the construction of equilibria in three-dimensional (3D) configurations. In MRxMHD, the plasma is sliced into sub-volumes separated by ideal interfaces, each undergoing relaxation, allowing the formation of islands and chaos. The resulting equilibrium has a stepped pressure profile across sub-volumes. The Stepped Pressure Equilibrium Code (SPEC) [S.R. Hudson et al., Phys. Plasmas 19, 112502 (2012)] was developed to calculate MRxMHD equilibria numerically. In this work, we have extended the SPEC code to compute MRxMHD equilibria with field-aligned flow and rotation, following the theoretical development to incorporate cross-helicity and angular momentum constraints. The code has been verified for convergence and compared to a Grad-Shafranov solver in 2D. We apply our new tool to study the flow profile change before and after the sawtooth crash of a reversed-field pinch discharge, in which data of the parallel flow is available. We find the promising result that under the constraints of cross-helicity and angular momentum, the parallel flow profile in post-crash SPEC equilibrium is flat in the plasma core and the amplitude of the flow matches experimental observations. Finally, we provide an example equilibrium with a 3D helical field structure as the favoured lower energy state. This will be the first 3D numerical equilibrium in which the flow effects are self-consistently calculated.
- Subjects :
- Physics
Angular momentum
Field (physics)
Reversed field pinch
FOS: Physical sciences
Mechanics
Condensed Matter Physics
01 natural sciences
Physics - Plasma Physics
010305 fluids & plasmas
Plasma Physics (physics.plasm-ph)
Amplitude
Nuclear Energy and Engineering
Flow (mathematics)
Physics::Plasma Physics
0103 physical sciences
Pinch
Relaxation (physics)
Magnetohydrodynamics
010306 general physics
Subjects
Details
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....efee95661afbbf22706d78556045347a
- Full Text :
- https://doi.org/10.48550/arxiv.2001.06984