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Related papers: Shear Alfven wave continuous spectrum within magne…

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The radial structure of the continuous spectrum of shear Alfven modes is calculated in the presence of a magnetic island in tokamak plasmas. Modes with the same helicity of the magnetic island are considered in a slab model approximation.…

Plasma Physics · Physics 2015-05-19 Alessandro Biancalani , Liu Chen , Francesco Pegoraro , Fulvio Zonca

The shear Alfv\'en continuum spectrum is studied for a tokamak with a single island chain using the ideal Magnetohydrodynamics (MHD) theory. We have taken into account the toroidal geometry and toroidal mode coupling with the island…

Plasma Physics · Physics 2022-12-28 Zhisong Qu , Matthew Hole

The shear Alfv\'en spectrum is computed in the presence of symmetry breaking perturbations that introduce chaotic magnetic field trajectories. Quadratic flux minimised surfaces allow the creation of pseudo straight field line coordinates in…

Plasma Physics · Physics 2025-12-01 Matthew Thomas , Zhisong Qu , Matthew Hole

The equations describing the continuous spectrum of shear Alfv\'en and ion sound waves propagating along magnetic field lines are introduced and solved in the ballooning space for general geometry in the ideal MHD limit. This approach is…

Plasma Physics · Physics 2019-09-11 Matteo Valerio Falessi , Nakia Carlevaro , Valeria Fusco , Gregorio Vlad , Fulvio Zonca

Using a 2D Viscoresistive Reduced MagnetoHydroDynamic (VR-RMHD) model, the magnetic island coalescence problem is studied in the presence of in-plane, parallel shear flows. Extending the analytical work of Waelbroeck et al [33] and…

Plasma Physics · Physics 2021-10-14 Jagannath Mahapatra , Arkaprava Bokshi , Rajaraman Ganesh , Abhijit Sen

Characterizing the gap eigenmode of shear Alfv\'{e}n waves (SAW) and its interaction with energetic ions is important to the success of magnetically confined fusion. Previous studies have reported an experimental observation of the spectral…

Plasma Physics · Physics 2018-11-30 Lei Chang

High-order plasma shaping (mainly elongation and shift, as opposed to low-order toroidicity) is shown, under certain conditions, to open gaps in the coupled shear-Alfv\'{e}n and acoustic continua at frequencies significantly above the…

Plasma Physics · Physics 2021-07-30 Paulo Rodrigues , Francesca Cella

We performed three-dimensional magnetohydrodynamic simulations of shear Alfven waves in a full field line system with magnetosphere-ionosphere coupling and plasma non-uniformities. Feedback instability of the Alfven resonant modes showed…

Space Physics · Physics 2015-06-23 Yasutaka Hiraki

The propagation of shear Alfven wave packets in inhomogeneous magnetic fields, at the origin of their distortion, regardless of the occurrence of non-linear coupling, is considered. It is shown that the distortion mechanism can be regarded…

Astrophysics · Physics 2008-10-23 Nicolas Bian , David Tsiklauri

We present a mechanism for the formation of the low frequency 1/f magnetic spectrum based on numerical solutions of a shell reduced-MHD model of the turbulent dynamics inside the sub-Alfv\'enic solar wind. We assign reasonably realistic…

Solar and Stellar Astrophysics · Physics 2015-06-04 A. Verdini , R. Grappin , R. Pinto , M. Velli

The dynamic evolution of coronal mass ejection (CME) in interplanetary space generates highly turbulent, compressed, and heated shock-sheath. This region furnishes a unique environment to study the turbulent fluctuations at the small scales…

Solar and Stellar Astrophysics · Physics 2022-09-13 Anil Raghav , Zubair Shaikh , Omkar Dhamane , Kalpesh Ghag , Prathmesh Tari , Utsav Panchal

We have extended our study of the competition between the drive and stabilization of plasma microinstabilities by sheared flow to include electromagnetic effects at low plasma $\beta$ (the ratio of plasma to magnetic pressure). The extended…

Plasma Physics · Physics 2015-06-16 M. D. J. Cole , S. L. Newton , S. C. Cowley , N. F. Loureiro , D. Dickinson , C. Roach , J. W. Connor

The effect of magnetic shear and shear flow on local gravitationally induced instabilities is investigated. A simple model is constructed allowing for an arbitrary entropy gradient and a shear plasma flow in the Boussinesq approximation. A…

Astrophysics · Physics 2009-11-06 Gregory G. Howes , Steven C. Cowley , James C. McWilliams

In this paper we investigate spectral and phase coherence properties of magnetic fluctuations in the vicinity of the spectral transition from large, magnetohydrodynamic (MHD) to sub-ion scales using in-situ measurements of the Wind…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sonny Lion , Olga Alexandrova , Arnaud Zaslavsky

The possibility of velocity shear-induced linear transformations of different magnetohydrodynamic waves in the solar wind is studied both analytically and numerically. A quantitative analysis of the wave transformation processes for all…

Astrophysics · Physics 2011-02-11 Grigol Gogoberidze , Andria Rogava , Stefaan Poedts

We show that a helical shear flow of a magnetized plasma may serve as an efficient amplifier of Alfven waves. We find that even when the flow is purely ejectional (i.e., when no rotation is present) Alfven waves are amplified through the…

Astrophysics · Physics 2009-11-07 Andria D. Rogava , Swadesh M. Mahajan , Gianluigi Bodo , Silvano Massaglia

In a magnetised plasma on scales well above ion kinetic scales, any constant-magnitude magnetic field, accompanied by parallel Alfv\'enic flows, forms a nonlinear solution in an isobaric, constant-density background. These structures, which…

Solar and Stellar Astrophysics · Physics 2022-09-01 Jonathan Squire , Alfred Mallet

In this paper, we consider the generation of magnetic island for the linearized MHD equations around the steady flowing plasma with velocity field $U_s=(u(y),0)$ and magnetic field $H_s=(b(y),0)$ in the finite channel.

Analysis of PDEs · Mathematics 2022-03-30 Cuili Zhai , Zhifei Zhang , Weiren Zhao

In the context of resonant absorption, nonlinearity has two different manifestations. The first is the reduction in amplitude of perturbations around the resonant point (wave energy absorption). The second is the generation of mean shear…

Solar and Stellar Astrophysics · Physics 2010-06-18 C. T. M. Clack , I. Ballai

Alfv\'{e}nic turbulent cascade perpendicular and parallel to the background magnetic field is studied accounting for anisotropic dispersive effects and turbulent intermittency. The perpendicular dispersion and intermittency make the…

Earth and Planetary Astrophysics · Physics 2016-03-23 J. S. Zhao , Y. M. Voitenko , D. J. Wu , M. Y. Yu
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