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Related papers: Shear Alfven wave continuous spectrum within magne…

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The shear Alfv\'en wave (SAW) continuum plays a critical role in the stability of energetic particle-driven Alfv\'{e}n eigenmodes. We develop a theoretical framework to analyze the SAW continuum in three-dimensional quasisymmetric magnetic…

Although it is well recognized that waves propagating in periodic media have forbidden gaps in the continuous spectrum, it is still yet unknown about the minimum number and depth of periodic modulations for clear spectral formation. This…

Plasma Physics · Physics 2018-11-30 Lei Chang

We analyse the effects of the propagating Alfv\'en waves, arising due to non-zero mean magnetic fields, on the nonequilibrium steady states of three-dimensional (3d) homogeneous Magnetohydrodynamic (MHD) turbulence. In particular, the…

Statistical Mechanics · Physics 2009-11-11 Abhik Basu , Jayanta K Bhattacharjee

The aim of the present study is to shed light on the effects connected with thermal misbalance due to non-equal cooling and heating rates induced by density and temperature perturbations in solar active regions hosting either propagating…

Solar and Stellar Astrophysics · Physics 2022-07-21 S. A. Belov , S. Vasheghani Farahani , N. E. Molevich

Large-amplitude Alfv\'en waves are ubiquitous in space plasmas and a main component of magnetohydrodynamic (MHD) turbulence in the heliosphere. As pump waves they are prone to parametric instability by which they can generate cyclotron and…

Plasma Physics · Physics 2012-01-16 Eckart Marsch , Daniel Verscharen

In the present paper, we investigate the power-law behaviour of the magnetic field spectra in the Earths magnetosheath region using Cluster spacecraft data under solar minimum condition. The power spectral density of the magnetic field data…

We perform idealised numerical simulations of magnetic buoyancy instabilities in a model of the solar tachocline. We introduce a simplified model of magnetic flux pumping in an upper layer (the convection zone), and study the effects of its…

Solar and Stellar Astrophysics · Physics 2015-06-04 Adrian J. Barker , Lara J. Silvers , Michael R. E. Proctor , Nigel O. Weiss

We consider a series of MHD simulations in which a small amplitude, transverse velocity perturbation is introduced into a complex magnetic field. We analysed the deformation of the wave fronts as the perturbation propagates through the…

Solar and Stellar Astrophysics · Physics 2019-09-11 Thomas Howson , Ineke De Moortel , Jack Reid , Alan Hood

A conservative scheme has been formulated and verified for gyrokinetic particle simulations of electromagnetic waves and instabilities in magnetized plasmas. An electron continuity equation derived from drift kinetic equation is used to…

Plasma Physics · Physics 2018-03-14 J. Bao , Z. Lin , Z. X. Lu

Small-scale magnetic turbulence observed by the Cluster spacecraft in the plasma sheet is investigated by means of a wavelet estimator suitable for detecting distinct scaling characteristics even in noisy measurements. The spectral…

A two-field Hamiltonian gyrofluid model for kinetic Alfv\'en waves retaining ion finite Larmor radius corrections and parallel magnetic field fluctuations is used to study direct turbulent cascades from the MHD to the sub-ion scales. For…

Space Physics · Physics 2022-06-13 T. Passot , P. L. Sulem , D. Laveder

In this work, the FALCON code is adopted for illustrating the features of shear Alfv\'en and continuous spectra in toroidal fusion plasmas. The FALCON codes employs the local Floquet analysis discussed in [Phys. of Plasmas \textbf{26} (8),…

Plasma Physics · Physics 2020-04-29 M. V. Falessi , N. Carlevaro , V. Fusco , E. Giovannozzi , P. Lauber , G. Vlad , F. Zonca

Using two-dimensional hybrid-kinetic simulations, we explore the nonlinear "interruption" of standing and traveling shear-Alfv\'en waves in collisionless plasmas. Interruption involves a self-generated pressure anisotropy removing the…

Plasma Physics · Physics 2017-12-14 J. Squire , M. W. Kunz , E. Quataert , A. A. Schekochihin

Alfven wave is the single most important physical phenomenon of magneto-hydrodynamic turbulence and has far-reaching impact to almost all studies related to astrophysical magnetic field. Yet the restoration of the Alfven wave fluctuations…

Astrophysics of Galaxies · Physics 2023-02-01 Ka Ho Yuen , Huirong Yan , Alex Lazarian

The linear dynamics of Alfven modes in tokamaks is investigated here by means of the global gyrokinetic particle-in-cell code NEMORB. The model equations are shown and the local shear Alfven wave dispersion relation is derived, recovering…

Plasma Physics · Physics 2016-02-17 A. Biancalani , A. Bottino , S. Briguglio , A. Koenies , Ph. Lauber , A. Mishchenko , E. Poli , B. D. Scott , F. Zonca

We study theoretically mode conversion and resonant overreflection of magnetohydrodynamic waves in an inhomogeneous plane-stratified plasma in the presence of a nonuniform shear flow, using precise numerical calculations of the reflection…

Plasma Physics · Physics 2022-12-21 Seulong Kim , Kihong Kim

An isolated, isothermal, and wide magnetic flux tube embedded either in the solar chromosphere or in the lower solar corona is considered, and the propagation of linear torsional Alfv'en waves is investigated. It is shown that the wideness…

Solar and Stellar Astrophysics · Physics 2020-08-25 Swati Routh , Z. E. Musielak , M. N. Sundar , Sai Sravanthi Joshi , Sree Charan

Rockets and satellites have previously observed small-scale Alfv\'en waves inside large-scale downward field-aligned currents and numerical simulations have associated their formation with self-consistent magnetosphere-ionosphere coupling.…

Space Physics · Physics 2013-04-05 Alexander J. B. Russell , Andrew N. Wright

Large-amplitude Alfv\'en waves are observed in various systems in space and laboratories, demonstrating an interesting property that the wave shapes are stable even in the nonlinear regime. The ideal magnetohydrodynamics (MHD) model…

Plasma Physics · Physics 2016-03-23 Hamdi M. Abdelhamid , Zensho Yoshida

{This work aims to investigate the spectral structure of the parallel electric field generated by strong anisotropic and balanced Alfvenic turbulence in relation with the problem of electron acceleration from the thermal population in solar…

Solar and Stellar Astrophysics · Physics 2015-05-19 N. H. Bian , E. P. Kontar , J. C. Brown