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Related papers: Current Singularities at Quasi-Separatrix Layers a…

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This paper considers the current distributions that derive from finite amplitude perturbations of line-tied magnetic fields comprising hyperbolic field structures. The initial equilibrium on which we principally focus is a planar magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-19 I. J. D. Craig , D. I. Pontin

Starting from an exact, steady-state, force-free solution of the magnetohydrodynamic (MHD) equations, we investigate how resistive current layers are induced by perturbing line-tied three-dimensional magnetic equilibria. This is achieved by…

Solar and Stellar Astrophysics · Physics 2016-01-12 Frederic Effenberger , I. J. D. Craig

Three-dimensional (3D) magnetohydrodynamic simulations are carried out to explore magnetic reconnections in the presence of 3D magnetic nulls and quasi-separatrix layers (QSLs). The initial magnetic fields are created by superposing uniform…

Solar and Stellar Astrophysics · Physics 2021-02-10 Sanjay Kumar , Sushree S. Nayak , Avijeet Prasad , Ramit Bhattacharyya

We provide a valid magnetohydrostatic equilibrium from the collapse of a 2D X-point in the presence of a finite plasma pressure, in which the current density is not simply concentrated in an infinitesimally thin, one-dimensional current…

Solar and Stellar Astrophysics · Physics 2013-09-13 Jorge Fuentes-Fernández , Clare E. Parnell , Alan W. Hood

Separators, which are in many ways the three-dimensional equivalent to two-dimensional nulls, are important sites for magnetic reconnection. Magnetic reconnection occurs in strong current layers which have very short length scales. The aim…

Solar and Stellar Astrophysics · Physics 2014-12-17 J. E. H. Stevenson , C. E. Parnell , E. R. Priest , A. L. Haynes

We revisit Parker's conjecture of current singularity formation in 3D line-tied plasmas using a recently developed numerical method, variational integration for ideal magnetohydrodynamics in Lagrangian labeling. With the frozen-in equation…

Plasma Physics · Physics 2018-01-03 Yao Zhou , Yi-Min Huang , Hong Qin , A. Bhattacharjee

Context: The majority of studies on stressed 3D magnetic null points consider magnetic reconnection driven by an external perturbation, but the formation of a genuine current sheet equilibrium remains poorly understood. This problem has…

Solar and Stellar Astrophysics · Physics 2012-09-07 Jorge Fuentes-Fernandez , Clare E. Parnell

In this paper we study current accumulations in 3D "tilted" nulls formed by a folding of the spine and fan. A non-zero component of current parallel to the fan is required such that the null's fan plane and spine are not perpendicular. Our…

Solar and Stellar Astrophysics · Physics 2013-09-13 Jorge Fuentes-Fernandez , Clare E. Parnell

The formation of a thin current sheet in a magnetic quasi-separatrix layer (QSL) is investigated by means of numerical simulation using a simplified ideal, low-$\beta$, MHD model. The initial configuration and driving boundary conditions…

Plasma Physics · Physics 2014-10-27 Frederic Effenberger , Kay Thust , Lukas Arnold , Rainer Grauer , Jürgen Dreher

The squashing factor Q (Titov et al. 2002), a property of the magnetic field line mapping, has been suggested as an indicator for the formation of current sheets, and subsequently magnetic reconnection, in astrophysical plasmas. Here we…

Solar and Stellar Astrophysics · Physics 2015-05-13 A. L. Wilmot-Smith , G. Hornig , D. I. Pontin

The presence of current singularities in a quasisymmetric magnetic field is explored. Quasisymmetry is shown effective in isolating Pfirsch-Schl\"{u}ter singularities, to leading order, to a single magnetic surface resonant with the…

Plasma Physics · Physics 2021-09-22 Eduardo Rodríguez , Amitava Bhattacharjee

Coronal heating has been a long-standing conundrum in solar physics. Parker's conjecture that spontaneous current singularities lead to nanoflares that heat the corona has been controversial. In ideal magnetohydrodynamics (MHD), can genuine…

Plasma Physics · Physics 2017-08-30 Yao Zhou

Recently a variational integrator for ideal magnetohydrodynamics in Lagrangian labeling has been developed. Its built-in frozen-in equation makes it optimal for studying current sheet formation. We use this scheme to study the…

Plasma Physics · Physics 2016-02-22 Yao Zhou , Yi-Min Huang , Hong Qin , A. Bhattacharjee

Singular currents typically appear on rational surfaces in non-axisymmetric ideal magnetohydrodynamic equilibria with a continuum of nested flux surfaces and a continuous rotational transform. These currents have two components: a surface…

Plasma Physics · Physics 2024-02-13 Yi-Min Huang , Yao Zhou , Joaquim Loizu , Stuart Hudson , Amitava Bhattacharjee

The nature of the evolution of the magnetic field, and of current sheet formation, at three-dimensional (3D) magnetic null points is investigated. A kinematic example is presented which demonstrates that for certain evolutions of a 3D null…

Astrophysics · Physics 2009-11-13 D. I. Pontin , A. Bhattacharjee , K. Galsgaard

To systematically stress a rotationally symmetric 3D magnetic null point by advecting the opposite footpoints of the spine axis in opposite directions. This stress eventually concentrates in the vicinity of the null point forming a local…

Solar and Stellar Astrophysics · Physics 2015-05-27 K. Galsgaard , D. I. Pontin

The behaviour of magnetic perturbations of an initially potential three-dimensional equilibrium magnetic null point are investigated. The basic components which constitute a typical disturbance are taken to be rotations and shears, in line…

Astrophysics · Physics 2008-11-26 D. I. Pontin , K. Galsgaard

The compression or expansion of a magnetic field that is initially potential is considered. It was recently suggested by Janse & Low [2009, ApJ, 690, 1089] that, following the volumetric deformation, the relevant lowest energy state for the…

Solar and Stellar Astrophysics · Physics 2015-06-05 D. I. Pontin , Y. -M. Huang

We investigate the existence of magnetohydrostatic equilibria for topologically complex magnetic fields. The approach employed is to perform ideal numerical relaxation experiments. We use a newly-developed Lagrangian relaxation scheme that…

Solar and Stellar Astrophysics · Physics 2017-10-19 Simon Candelaresi , David Pontin , Gunnar Hornig

The performed magnetohydrodynamic simulation examines the importance of magnetofluid evolution which naturally leads to current sheets in the presence of three-dimensional (3D) magnetic nulls. Initial magnetic field is constructed by…

Solar and Stellar Astrophysics · Physics 2017-06-20 Sanjay Kumar , R. Bhattacharyya
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