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Related papers: Relaxed MHD states of a multiple region plasma

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A unified energy principle approach is presented for analysing the magnetohydrodynamic (MHD) stability of plasmas consisting of multiple ideal and relaxed regions. By choosing an appropriate gauge, we show that the plasma displacement…

Plasma Physics · Physics 2015-05-13 R. L. Mills , M. J. Hole , R. L. Dewar

We show that the variational energy principle of multi-region relaxed magnetohydrodynamic (MRxMHD) model can be used to predict finite-pressure linear tearing instabilities. In this model, the plasma volume is sliced into sub-volumes…

Plasma Physics · Physics 2023-06-07 A. Kumar , J. Loizu , M. J. Hole , Z. Qu , S. R. Hudson , R. L Dewar

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…

Plasma Physics · Physics 2020-05-20 Z. S. Qu , R. L. Dewar , F. Ebrahimi , J. K. Anderson , S. R. Hudson , M. J. Hole

A general formulation of the problem of calculating the spectrum of stable and unstable eigenmodes of linearized perturbations about a magnetically confined toroidal plasma is presented. The analysis is based on a new hydromagnetic…

Plasma Physics · Physics 2017-03-07 Robert L Dewar , Li Huey Tuen , Matthew J Hole

Calculations of tearing mode stability in tokamaks split conveniently into an external region, where marginally stable ideal MHD is applicable, and a resonant layer around the rational surface where sophisticated kinetic physics is needed.…

Plasma Physics · Physics 2014-08-13 C J Ham , J W Connor , S C Cowley , R J Hastie , T C Hender , Y Q Liu

We show the stepped-pressure equilibria that are obtained from a generalization of Taylor relaxation known as multi-region, relaxed MHD (MRXMHD) are also generalizations of ideal MHD. We show this by proving that as the number of plasma…

Plasma Physics · Physics 2013-06-25 G. R. Dennis , S. R. Hudson , R. L. Dewar , M. J. Hole

We present an extension of the multi-region relaxed magnetohydrodynamics (MRxMHD) equilibrium model that includes plasma flow. This new model is a generalization of Woltjer's model of relaxed magnetohydrodynamics equilibria with flow. We…

Plasma Physics · Physics 2014-04-04 G. R. Dennis , S. R. Hudson , R. L. Dewar , M. J. Hole

The equilibrium of a finite-beta RFP plasma in the presence of saturated-amplitude tearing modes is investigated. The singularities of the MHD force balance equation JXB=grad(p) at the modes rational surfaces are resolved through a proper…

Plasma Physics · Physics 2009-11-07 P. Zanca , F. Sattin

The equilibrium of a finite-beta cylindrical RFP plasma in the presence of saturated-amplitude tearing modes is investigated. The singularities arising from the perturbative analysis of the MHD force balance equation JxB=grad(p) are…

Plasma Physics · Physics 2007-05-23 P. Zanca , F. Sattin , E. Martines

During the 2003 experimental campaign, the aim of realizing reliable fully non inductive discharges has been successfully completed in Tore Supra. One the major difficulties in optimizing this scenario comes from MHD stability issues.…

Plasma Physics · Physics 2009-11-10 P. Maget , F. Imbeaux , G. Huysmans , Ph. Moreau , M. Ottaviani , J. -L. Segui

The rapid deposition of energy by Edge Localised Modes (ELMs) onto plasma facing components, is a potentially serious issue for large Tokamaks such as ITER and DEMO. The trigger for ELMs is believed to be the ideal Magnetohydrodynamic…

Plasma Physics · Physics 2009-02-23 A. J. Webster , C. G. Gimblett

This paper studies the nonlinear evolution of magnetic field turbulence in proximity of steady ideal MHD configurations characterized by a small electric current, a small plasma flow, and approximate flux surfaces, a physical setting that…

Plasma Physics · Physics 2024-09-12 Naoki Sato , Michio Yamada

Motivated by explosive releases of energy in fusion, space and astrophysical plasmas, we consider the nonlinear stability of stratified magnetohydrodynamic (MHD) equilibria against two-dimensional interchanges of straight magnetic-flux…

High Energy Astrophysical Phenomena · Physics 2024-12-10 David N. Hosking , David Wasserman , Steven C. Cowley

We describe the construction of stepped-pressure equilibria as extrema of a multi-region, relaxed magnetohydrodynamic (MHD) energy functional that combines elements of ideal MHD and Taylor relaxation, and which we call MRXMHD. The model is…

Plasma Physics · Physics 2015-06-12 S. R. Hudson , R. L. Dewar , G. Dennis , M. J. Hole , M. McGann , G. von Nessi , S. Lazerson

Type-I Edge Localised Modes (ELMs) have been mitigated in MAST through the application of n = 3, 4 and 6 resonant magnetic perturbations (RMPs). For each toroidal mode number of the non-axisymmetric applied fields, the frequency of the ELMs…

The adiabatic limit of a recently proposed dynamical extension of Taylor relaxation, \emph{multi-region relaxed magnetohydrodynamics} (MRxMHD) is summarized, with special attention to the appropriate definition of relative magnetic…

Plasma Physics · Physics 2017-04-05 Robert L. Dewar , Stuart R. Hudson , Amitava Bhattacharjee , Zensho Yoshida

Accurate modeling of core instabilities in tokamak plasmas is essential to understand the underlying physical mechanisms and their impact on plasma confinement. The ideal stability of the internal kink mode and the m = 1 collisionless…

The recent formulations of multi-region relaxed magnetohydrodynamics (MRxMHD) have generalized the famous Woltjer-Taylor states by incorporating a collection of "ideal barriers" that prevent global relaxation, and flow. In this paper, we…

Plasma Physics · Physics 2016-08-04 Manasvi Lingam , Hamdi M. Abdelhamid , Stuart R. Hudson

The fluid dynamics community has found success in explaining both the onset and coherent structure formation in wall-bounded turbulence through examining transient growth and pseudoresonance. Whether similar effects are important in plasmas…

Plasma Physics · Physics 2024-11-01 Elias Pratschke

We present a discussion of two-dimensional magneto-hydrodynamics (MHD) configurations, concerning the equilibria of accretion disks of a strongly magnetized astrophysical object. We set up a viscoresistive scenario which generalizes…

High Energy Astrophysical Phenomena · Physics 2010-07-30 Giovanni Montani , Riccardo Benini
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