English
Related papers

Related papers: Twisted coronal loops in uniform gravity

200 papers

Turbulence is often invoked to explain the origin of nonthermal particles in space and astrophysical plasmas. By means of 3D fully kinetic particle-in-cell simulations, we demonstrate that turbulence in low-$\beta$ plasmas ($\beta$ is the…

High Energy Astrophysical Phenomena · Physics 2022-09-16 Luca Comisso , Lorenzo Sironi

We study the interplay among cooling, heating, conduction, and magnetic fields in gravitationally stratified plasmas using simplified, plane-parallel numerical simulations. Since the physical heating mechanism remains uncertain in massive…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-05 Michael McCourt , Prateek Sharma , Eliot Quataert , Ian J. Parrish

(abridged) The physics of the pulsar magnetosphere near the neutron star surface remains poorly constrained by observations. Nevertheless it is believed that large vacuum gaps exist in the magnetosphere, and a non-neutral plasma partially…

High Energy Astrophysical Phenomena · Physics 2015-05-13 J. Petri

The 1998 April 20 spectral line data from the Coronal Diagnostics Spectrometer (CDS) on the {\it Solar and Heliospheric Observatory} (\SOHO) shows a coronal loop on the solar limb. Our original analysis of these data showed that the plasma…

Astrophysics · Physics 2009-11-11 J. T. Schmelz , K. Nasraoui , V. L. Richardson , P. J. Hubbard , C. R. Nevels , J. E. Beene

In a collisionless, magnetized plasma, particles may stream freely along magnetic-field lines, leading to phase "mixing" of their distribution function and consequently to smoothing out of any "compressive" fluctuations (of density,…

Plasma Physics · Physics 2019-03-27 Romain Meyrand , Anjor Kanekar , William Dorland , Alexander A. Schekochihin

We discuss some aspects of magnetic reconnection which could help in understanding many aspects of magnetic plasma interactions. We will show that the helical structure often observed in polar jets is a natural consequence of magnetic…

Solar and Stellar Astrophysics · Physics 2015-05-27 Ehsan Tavabi , Serge Koutchmy , Ali Ajabshirizadeh

Our aim is to model the 3D magnetic field structure of the upper solar atmosphere, including regions of non-negligible plasma beta. We use high-resolution photospheric magnetic field measurements from SUNRISE/IMaX as boundary condition for…

Solar and Stellar Astrophysics · Physics 2015-12-09 T. Wiegelmann , T. Neukirch , D. H. Nickeler , S. K. Solanki , V. Martinez Pillet , J. M. Borrero

Damped transverse oscillations of magnetic loops are routinely observed in the solar corona. This phenomenon is interpreted as standing kink magnetohydrodynamic waves, which are damped by resonant absorption owing to plasma inhomogeneity…

Solar and Stellar Astrophysics · Physics 2015-10-28 Roberto Soler , Manuel Luna

Relaxations of localized over-density in a plane transverse to the magnetic field are numericallyinvestigated under the effect of drift-wave and interchange drives in SOL conditions. Such a controlleddeparture from thermodynamic equilibrium…

Plasma Physics · Physics 2024-06-06 R Varennes , G Dif-Pradalier , P Ghendrih , V Grandgirard , O Panico , Y Sarazin , E Serre , D Zarzoso

We present a series of numerical simulations of the quiet Sun plasma threaded by magnetic fields that extend from the upper convection zone into the low corona. We discuss an efficient, simplified approximation to the physics of optically…

Solar and Stellar Astrophysics · Physics 2015-05-27 William P. Abbett , George H. Fisher

We investigate the nature of transverse kink oscillations of loops expanding through the solar corona and how can oscillations be used to diagnose the plasma parameters and the magnetic field. In particular, we aim to analyse how the…

Solar and Stellar Astrophysics · Physics 2015-06-05 Istvan Ballai , Beniamin Orza

It is known that magnetic perturbations can mitigate edge localized modes (ELMs) in experiments, for example MAST (Kirk et al 2013 Nucl. Fusion 53 043007). One hypothesis is that the magnetic perturbations cause a three dimensional…

Plasma Physics · Physics 2015-10-29 C J Ham , I T Chapman , A Kirk , S Saarelma

We present results of 2.5D numerical simulations of the emergence of sub-surface magnetic flux into the solar atmosphere, with emerging flux regions ranging from $10^{18}$ to $10^{21}$ Mx, representing both ephemeral and active regions. We…

Solar and Stellar Astrophysics · Physics 2015-06-12 James E. Leake , Mark G. Linton

A pair of curved shocks in a collisionless plasma is examined with a two-dimensional particle-in-cell (PIC) simulation. The shocks are created by the collision of two electron-ion clouds at a speed that exceeds everywhere the threshold…

High Energy Astrophysical Phenomena · Physics 2015-07-14 M. E. Dieckmann , A. Bock , H. Ahmed , D. Doria , G. Sarri , A. Ynnerman , M. Borghesi

Stabilization is still a somewhat controversial issue concerning its very existence and also the precise conditions for its occurrence. The key quantity to settle these questions is the ionization probability, for which hitherto no…

Atomic Physics · Physics 2007-05-23 C. Figueira de Morisson Faria , A. Fring , R. Schrader

This work addresses the problem of plasma condensation and ``catastrophic cooling'' in solar coronal loops. We have carried out numerical calculations of coronal loops and find several classes of time-dependent solutions (static, periodic,…

Astrophysics · Physics 2009-11-10 D. A. N. Mueller , H. Peter , V. H. Hansteen

The author presents a model for variability of the flux and polarization of blazars in which turbulent plasma flowing at a relativistic speed down a jet crosses a standing conical shock. The shock compresses the plasma and accelerates…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Alan P. Marscher

We analyse transverse oscillations of a coronal loop excited by continuous monoperiodic motions of the loop footpoint at different frequencies in the presence of gravity. Using the MPI-AMRVAC code, we perform three-dimensional numerical…

Solar and Stellar Astrophysics · Physics 2019-05-15 Andrey Afanasyev , Konstantinos Karampelas , Tom Van Doorsselaere

A concise review of observations of the $\alpha$ dynamo effect in laboratory plasmas is given. Unlike many astrophysical systems, the laboratory pinch plasmas are driven magnetically. When the system is overdriven, the resultant…

Astrophysics · Physics 2021-06-29 Hantao Ji , Stewart C. Prager

Injection of coaxial-gun-formed magnetized plasmas into a background transverse vacuum magnetic field or into a background magnetized plasma has been studied in the helicon-cathode (HelCat) linear plasma device at the University of New…

Plasma Physics · Physics 2018-05-28 Yue Zhang , Dustin M. Fisher , Mark Gilmore , Scott C. Hsu , Alan G. Lynn