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

Lapenta, Giovanni; Skender, Marina

doi:10.1088/1367-2630/aa5de9

Cited by 2 publications

(3 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…the helical core observed in the hybrid mode of operation of the tokamak [143,223]. This type of dynamo is also present in a flux rope configuration susceptible to the kink instability [224].…”

Section: A New Interpretation Of the Mhd Dynamo: The Electrostatic Dy...mentioning

confidence: 85%

The reversed field pinch

et al. 2021

View full text Add to dashboard Cite

This paper reviews the research on the reversed field pinch (RFP) in the last three decades. Substantial experimental and theoretical progress and transformational changes have been achieved since the last review (Bodin 1990 Nucl. Fusion 30 1717–37). The experiments have been performed in devices with different sizes and capabilities. The largest are RFX-mod in Padova (Italy) and MST in Madison (USA). The experimental community includes also EXTRAP-T2R in Sweden, RELAX in Japan and KTX in China. Impressive improvements in the performance are the result of exploration of two lines: the high current operation (up to 2 MA) with the spontaneous occurrence of helical equilibria with good magnetic flux surfaces and the active control of the current profile. A crucial ingredient for the advancements obtained in the experiments has been the development of state-of-art active feedback control systems allowing the control of MHD instabilities in presence of a thin shell. The balance between achievements and still open issues leads us to the conclusion that the RFP can be a valuable and diverse contributor in the quest for fusion electricity.

show abstract

Section: A New Interpretation Of the Mhd Dynamo: The Electrostatic Dy...mentioning

confidence: 85%

The reversed field pinch

et al. 2021

View full text Add to dashboard Cite

show abstract

“…For instance, charge separation effects are included, even though the plasma will remain quasi-neutral in distances larger than the Debye length [3]. Recent observations confirm that electric fields created by small deviations from the quasi-neutral state can play an important role in tokamak dynamics [6,7]. However, from the numerical point of view the charge separation introduces dispersive waves at high frequency that are difficult to resolve numerically as they might have very different length and time scales compared to other waves present in the system.…”

Section: Linear Waves In Ideal Two-fluid Plasmamentioning

confidence: 97%

“…Additionally, the scales of the problem are considered to be much larger than the ion gyroradius, and the relative velocity between ion and electrons to be much smaller than the center of mass velocity [3]. These simplifications might be often violated in regions of the problem where the hydrodynamic and electromagnetic variables vary rapidly, e.g., magnetic reconnection [4], where the drift velocity effects are important [5], or when the plasma deviates from the quasi-neutral state, as observed in tokamaks [6,7]. In general, the two-fluid plasma model considers small deviations from the local thermodynamic equilibrium that are responsible for the transport fluxes, i.e., viscosity and thermal conduction.…”

Section: Introductionmentioning

confidence: 99%

Fully-implicit finite volume method for the ideal two-fluid plasma model

Laguna

Ozak

Lani

et al. 2018

Computer Physics Communications

View full text Add to dashboard Cite

We present a novel numerical model that simulates ideal two-fluid plasmas coupled to the full set of Maxwell's equations with application to space and laboratory plasmas. We use a fully-implicit finite volume method for unstructured meshes, that uses an advection upstream splitting method (i.e., AUSM +up) for all speeds to discretize the numerical fluxes of the fluids. In addition, we discretize Maxwell's equations with a modified-Rusanov scheme. The electromagnetic numerical dissipation is scaled using the scales of the fluid-electromagnetics coupled problem that are found to be very different from those of the uncoupled problem. Our numerical scheme guarantees that the elliptical constraints of Maxwell's equations are satisfied by using hyperbolic divergence cleaning. We validate the performance and accuracy of our model by simulating the following conventional cases: a circularly polarized wave, a Brio-Wu type shock tube, and a two-fluid plasma reconnection with the GEM challenge set up. Our model reveals the complexity of the two-fluid model compared to magnetohydrodynamics (MHD) models, as the inclusion of charge separation, the displacement current and the electron dynamics present are ignored by the MHD simplifications. The two-fluid model shows the presence of electromagnetic and plasma waves and the effect that they have in even the simplest cases. We also compare our model to other available two-fluid models and find our results to be in good agreement.

show abstract

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

Cited by 2 publications

References 15 publications

The reversed field pinch

The reversed field pinch

Fully-implicit finite volume method for the ideal two-fluid plasma model

Contact Info

Product

Resources

About