skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Multi-region relaxed magnetohydrodynamics in plasmas with slowly changing boundaries -- Resonant response of a plasma slab

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4979350· OSTI ID:1358665
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [3];  [4]
  1. Australian National Univ., Canberra, ACT (Australia)
  2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  3. Princeton Univ., NJ (United States). Dept. of Astrophysical Sciences; Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  4. Univ. of Tokyo (Japan)

The adiabatic limit of a recently proposed dynamical extension of Taylor relaxation, multi-region relaxed magnetohydrodynamics (MRxMHD), is summarized, with special attention to the appropriate definition of a relative magnetic helicity. The formalism is illustrated using a simple two-region, sheared-magnetic-field model similar to the Hahm-Kulsrud-Taylor (HKT) rippled-boundary slab model. In MRxMHD, a linear Grad-Shafranov equation applies, even at finite ripple amplitude. The adiabatic switching on of boundary ripple excites a shielding current sheet opposing reconnection at a resonant surface. The perturbed magnetic field as a function of ripple amplitude is calculated by invoking the conservation of magnetic helicity in the two regions separated by the current sheet. Here, at low ripple amplitude, "half islands" appear on each side of the current sheet, locking the rotational transform at the resonant value. Beyond a critical amplitude, these islands disappear and the rotational transform develops a discontinuity across the current sheet. Published by AIP Publishing.

Research Organization:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
Contributing Organization:
Centre for Plasmas and Fluids, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 2601, Australia; Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8561, Japan; R.L.D. some travel support from Australian Research Council Grant No. DP11010288. The work of S.R.H. and A.B. was supported under U.S. DOE Grant No. DE-AC02-09CH11466 and that of Z.Y. was supported under JSPS Grant No. KAKENHI 23224014.
Grant/Contract Number:
AC02-09CH11466
OSTI ID:
1358665
Alternate ID(s):
OSTI ID: 1361799
Report Number(s):
PPPL-5373; Australian Research Council Grant No. DP11010288; JSPS Grant No. KAKENHI 23224014.
Journal Information:
Physics of Plasmas, Vol. 24, Issue 4; ISSN 1070-664X
Publisher:
American Institute of Physics (AIP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 5 works
Citation information provided by
Web of Science

References (50)

Current drive and helicity injection journal January 1984
An energy principle for hydromagnetic stability problems
  • Bernstein, I. B.; Frieman, E. A.; Kruskal, Martin David
  • Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, Vol. 244, Issue 1236, p. 17-40 https://doi.org/10.1098/rspa.1958.0023
journal February 1958
The topological properties of magnetic helicity journal October 1984
Verification of the ideal magnetohydrodynamic response at rational surfaces in the VMEC code journal January 2016
Relaxed plasma-vacuum systems with pressure journal July 2003
Current density and plasma displacement near perturbed rational surfaces journal November 2010
Preconditioned descent algorithm for rapid calculations of magnetohydrodynamic equilibria journal September 1991
Relaxation and magnetic reconnection in plasmas journal July 1986
Representation of ideal magnetohydrodynamic modes journal February 2013
Rapid Change of Field line Connectivity and Reconnection in Stochastic Magnetic Fields journal September 2014
The relationship between the 'tangled discharge' and 'dynamo' models of the magnetic relaxation process journal October 1991
Hamilton–Jacobi theory for continuation of magnetic field across a toroidal surface supporting a plasma pressure discontinuity journal July 2010
Exact axisymmetric Taylor states for shaped plasmas journal June 2014
Stepped pressure profile equilibria in cylindrical plasmas via partial Taylor relaxation journal December 2006
Magnetic islands and singular currents at rational surfaces in three-dimensional magnetohydrodynamic equilibria journal February 2015
Interaction between Hydromagnetic Waves and a Time-Dependent, Inhomogeneous Medium journal January 1970
Relativistic helicity and link in Minkowski space-time journal April 2014
Tokamak plasma high field side response to an n = 3 magnetic perturbation: a comparison of 3D equilibrium solutions from seven different codes journal May 2015
Forced magnetic reconnection journal January 1985
Existence and calculation of sharp boundary magnetohydrodynamic equilibrium in three-dimensional toroidal geometry journal January 1986
Variational formulation of relaxed and multi-region relaxed magnetohydrodynamics journal November 2015
Plasmoid solutions of the Hahm–Kulsrud–Taylor equilibrium model journal August 2013
Taylor relaxation in a torus of arbitrary aspect ratio and cross section journal January 1981
Minimum energy state of a toroidal discharge journal January 1980
Hydromagnetic stability of a diffuse linear pinch journal June 1960
Computation of multi-region relaxed magnetohydrodynamic equilibria journal November 2012
Helical bifurcation and tearing mode in a plasma—a description based on Casimir foliation journal August 2012
Motion of magnetic lines of force journal April 1958
Edge stability and transport control with resonant magnetic perturbations in collisionless tokamak plasmas journal May 2006
Woltjer-Taylor State without Taylor’s Conjecture: Plasma Relaxation at all Wavelengths journal December 2012
Formation of current singularity in a topologically constrained plasma journal February 2016
Saturation of the tearing mode journal January 1977
Pressure-driven amplification and penetration of resonant magnetic perturbations journal May 2016
Existence of three-dimensional ideal-magnetohydrodynamic equilibria with current sheets journal September 2015
2-D, nonlinear spectral simulation of reconnective transitions on a periodic, planar current sheet with (1) smooth and (2) corrugated conducting wall boundary conditions with flow journal May 1990
Toroidal Containment of a Plasma journal January 1967
Equilibria and stability in partially relaxed plasma–vacuum systems journal July 2007
Magnetohydrodynamic stability of plasmas with ideal and relaxed regions journal October 2009
The spectrum of multi-region-relaxed magnetohydrodynamic modes in topologically toroidal geometry journal February 2017
Hamilton's principle for a hydromagnetic fluid with a free boundary journal November 1978
Relaxation of Toroidal Plasma and Generation of Reverse Magnetic Fields journal November 1974
Preconditioned descent algorithm for rapid calculations of magnetohydrodynamic equilibria journal November 1990
Hamilton's principle for a hydromagnetic fluid with a free boundary report March 1978
Forced Magnetic Reconnection journal January 1982
Magnetohydrodynamic Stability of Plasmas with Ideal and Relaxed Regions text January 2009
Computation of multi-region relaxed magnetohydrodynamic equilibria text January 2012
Relativistic helicity and link in Minkowski space-time text January 2013
Variational formulation of relaxed and multi-region relaxed magnetohydrodynamics text January 2015
Formation of current singularity in a topologically constrained plasma text January 2015
Spectrum of multi-region-relaxed magnetohydrodynamic modes in topologically toroidal geometry text January 2016

Cited By (3)