Geometrical investigation of the kinetic evolution of the magnetic field in a periodic flux rope

Restante, Anna Lisa; Lapenta, Giovanni; Intrator, T.

doi:10.1063/1.4817167

Cited by 9 publications

(9 citation statements)

References 58 publications

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“…The single flux rope is modeled with a simple screw-pinch configuration [7] as in previous works [6,11]. In this configuration, the initial magnetic field in cylindrical coordinates is:…”

Section: Simulation Modelmentioning

confidence: 99%

Signatures of secondary collisionless magnetic reconnection driven by kink instability of a flux rope

Lapenta

Delzanno

Henri

et al. 2014

Plasma Phys. Control. Fusion

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Abstract. The kinetic features of secondary magnetic reconnection in a single flux rope undergoing internal kink instability are studied by means of three-dimensional Particle-in-Cell simulations. Several signatures of secondary magnetic reconnection are identified in the plane perpendicular to the flux rope: a quadrupolar electron and ion density structure and a bipolar Hall magnetic field develop in proximity of the reconnection region. The most intense electric fields form perpendicularly to the local magnetic field, and a reconnection electric field is identified in the plane perpendicular to the flux rope. An electron current develops along the reconnection line in the opposite direction of the electron current supporting the flux rope magnetic field structure. Along the reconnection line, several bipolar structures of the electric field parallel to the magnetic field occur making the magnetic reconnection region turbulent. The reported signatures of secondary magnetic reconnection can help to localize magnetic reconnection events in space, astrophysical and fusion plasmas.

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“…The single flux rope is modeled with a simple screw-pinch configuration [7] as in previous works [6,11]. In this configuration, the initial magnetic field in cylindrical coordinates is:…”

Section: Simulation Modelmentioning

confidence: 99%

Signatures of secondary collisionless magnetic reconnection driven by kink instability of a flux rope

Lapenta

Delzanno

Henri

et al. 2014

Plasma Phys. Control. Fusion

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“…To do so we focus on the kink instability as a paradigm for a number of processes in plasmas. Kink modes are key in space and astrophysical plasmas [6][7][8] and in the evolution of fusion devices [9]. For example, in the RFP fusion device [3,10] tearing and kink modes lead to a dynamo process that sustains the poloidal flux and the field reversal.…”

Section: Introductionmentioning

confidence: 99%

Role of electric fields in the MHD evolution of the kink instability

Lapenta

Skender

2017

New J. Phys.

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The discovery (Bonfiglio et al 2005 Phys. Rev. Lett. 94 145001) of electrostatic fields playing a crucial role in establishing plasma motion in the flux conversion and dynamo processes in reversed field pinches is revisited. In order to further elucidate the role of the electrostatic fields, a flux rope configuration susceptible to the kink instability is numerically studied with an MHD code. Simulated nonlinear evolution of the kink instability is found to confirm the crucial role of the electrostatic fields.A new insight is gained on the special function of the electrostatic fields: they lead the plasma towards the reconnection site at the mode resonant surface. Without this step the plasma column could not relax to its nonlinear state, since no other agent is present to perform this role. While the inductive field generated directly by the kink instability is the dominant flow driver, the electrostatic field is found to allow the motion in the vicinity of the reconnection region.

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“…The small red circle locates the gyration axis.that the separation between flux parent current and the reversed induced current in the x-y plane is on the order of 4 cm which is roughly the ion inertial length.Compared to the single fluid MHD picture, these show forces and dynamics on short length scales, and may represent dynamics on kinetic scales, or at least require some extended model for MHD-like fluid behavior. Massively parallel 3D kinetic simulations[50] of a periodic flux rope undergoing 136 Magnetic footprint of the flux rope, showing that J × B − ∇P = 0 does not cancel in about 25% of this measured surface. These data were taken at z = 40 cm from the gun, but similar conclusions hold for other cut planes at z = 25, 30, 35 cm, although not as clearly, perhaps because of the reversed current.…”

mentioning

confidence: 97%

Flux rope dynamics in three dimensions

Sears

Feng

Intrator

et al. 2014

Plasma Phys. Control. Fusion

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A large 3D data set has been assembled using the relaxation scaling experiment (RSX) device to study the dynamics of flux ropes. In a series of single flux rope experiments, we have measured induced eddy currents inside the plasma that complicate the evolution of a nominally simple current system. It is also likely that the nominal MHD force balance is violated on ion inertial length scales. These phenomena appear irreducibly three dimensional.

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Geometrical investigation of the kinetic evolution of the magnetic field in a periodic flux rope

Cited by 9 publications

References 58 publications

Signatures of secondary collisionless magnetic reconnection driven by kink instability of a flux rope

Signatures of secondary collisionless magnetic reconnection driven by kink instability of a flux rope

Role of electric fields in the MHD evolution of the kink instability

Flux rope dynamics in three dimensions

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