English
Related papers

Related papers: Negative Turbulent Magnetic Diffusivity $\beta$ ef…

200 papers

We construct a magnetic helicity conserving dynamo theory which incorporates a calculated magnetic helicity current. In this model the fluid helicity plays a small role in large scale magnetic field generation. Instead, the dynamo process…

Astrophysics · Physics 2009-10-31 Ethan T. Vishniac , Jungyeon Cho

The magnetic field in Hall plasmas is frozen in the electron component and is advected not only with the plasma motion but also with the electrical current flow. Its coupling with the plasma may be not as strong as characteristic of the MHD…

Astrophysics · Physics 2009-11-06 L. I. Rudakov

Transient interaction of magnetic dipole with plasma flow carrying southward magnetic field is studied in laboratory experiment. The flow with transverse frozen-in field is generated by means of laser-produced plasma cross-field expansion…

The term ``dynamo'' means different things to the laboratory fusion plasma and astrophysical plasma communities. To alleviate the resulting confusion and to facilitate interdisciplinary progress, we pinpoint conceptual differences and…

Astrophysics · Physics 2009-11-11 Eric G. Blackman , Hantao Ji

Understanding the in situ amplification of large scale magnetic fields in turbulent astrophysical rotators has been a core subject of dynamo theory. When turbulent velocities are helical, large scale dynamos that substantially amplify…

Fluid Dynamics · Physics 2012-06-22 Jonathan Pietarila Graham , Eric G. Blackman , Pablo D. Mininni , Annick Pouquet

We performed numerical simulations of magnetic reconnection with different strength of magnetic fields from the solar photosphere to the upper chromosphere. The main emphasis is to identify dominant mechanisms for heating plasmas in the…

Solar and Stellar Astrophysics · Physics 2025-06-24 Abdullah Zafar , Lei Ni , Kaifeng Kang , Guanchong Cheng , Jing Ye , Jun Lin , Ahmad Ali , Nadia Imtiaz

Dynamo action refers to energy exchange processes through which magnetic fields are generated at the expense of kinetic energy of the plasma flows. Dynamos can generate magnetic fields across scales larger or smaller than the flows…

In helical hydromagnetic turbulence with an imposed magnetic field (which is constant in space and time) the magnetic helicity of the field within a periodic domain is no longer an invariant of the ideal equations. Alternatively, there is a…

Astrophysics · Physics 2009-11-07 Axel Brandenburg , William H. Matthaeus

We suggest a new mechanism for generation of large-scale magnetic field in the hot plasma of early universe which is based on the parity violation in weak interactions and depends neither on helicity of matter turbulence resulting in the…

Astrophysics · Physics 2009-11-10 V. B. Semikoz , D. D. Sokoloff

We study the effect of the non-linear process of ambipolar diffusion (joint transport of magnetic flux and charged particles relative to neutral particles) on the long-term behavior of a non-uniform magnetic field in a one-dimensional…

Solar and Stellar Astrophysics · Physics 2015-05-18 Jaime Hoyos , Andreas Reisenegger , Juan Valdivia

We use three-dimensional direct numerical simulations of the helically forced magnetohydrodynamic equations in spherical shell segments in order to study the effects of changes in the geometrical shape and size of the domain on the growth…

Astrophysics · Physics 2010-01-15 Dhrubaditya Mitra , Reza Tavakol , Axel Brandenburg , David Moss

Large-scale magnetic fields in stars and galaxies are thought to arise by mean-field dynamo action due to the combined influence of both helical turbulence and shear. Those systems are also highly conducting and the turbulence therein leads…

Astrophysics of Galaxies · Physics 2019-05-22 Pallavi Bhat , Kandaswamy Subramanian , Axel Brandenburg

The recent study of Blackman and Subramanian (Paper I) indicates that large scale helical magnetic fields are resilient to turbulent diffusion in the sense that helical fields stronger than a critical value, decay on slow (~resistively…

Astrophysics of Galaxies · Physics 2015-06-17 Pallavi Bhat , Eric G. Blackman , Kandaswamy Subramanian

The influence of fluctuating conductivity on the coefficients known from the mean-field electrodynamics is considered. If the conductivity fluctuations are assumed as uncorrelated with the turbulent velocity field then only the effective…

Plasma Physics · Physics 2020-07-15 G. Rüdiger , M. Küker , P. J. Käpylä

From the near-Earth solar wind to the intracluster medium of galaxy clusters, collisionless, high-beta, magnetized plasmas pervade our universe. Energy and momentum transport from large-scale fields and flows to small scale motions of…

Solar magnetic fields comprise an 11-year activity cycle, represented by the number of sunspots. The maintenance of such a solar magnetic field can be attributed to fluid motion in the convection zone, i.e. a dynamo. This study conducts the…

Solar and Stellar Astrophysics · Physics 2022-08-24 Ryota Shimada , Hideyuki Hotta , Takaaki Yokoyama

In the presence of magnetic helicity, inverse transfer from small to large scales is well known in magnetohydrodynamic (MHD) turbulence and has applications in astrophysics, cosmology, and fusion plasmas. Using high resolution direct…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-23 Axel Brandenburg , Tina Kahniashvili , Alexander G. Tevzadze

Helical magnetohydrodynamic turbulence with Hall effects is ubiquitous in heliophysics and plasma physics, such as star formation and solar activities, and its intrinsic mechanisms are still not clearly explained. Direct numerical…

Plasma Physics · Physics 2024-05-07 Running Hu , Jin-Han Xie , Xinliang Li , Changping Yu , Yuan Hu , Jianchun Wang , Shiyi Chen

We report on a first-principles numerical and theoretical study of plasma dynamo in a fully kinetic framework. By applying an external mechanical force to an initially unmagnetized plasma, we develop a self-consistent treatment of the…

High Energy Astrophysical Phenomena · Physics 2023-08-07 Muni Zhou , Vladimir Zhdankin , Matthew W. Kunz , Nuno F. Loureiro , Dmitri A. Uzdensky

Magnetic fields in rotating and radiating astrophysical plasma can be produced due to a radiative interaction between plasma layers moving relative to each other. The efficiency of current drive, and with it the associated dynamo effect, is…

Plasma Physics · Physics 2017-09-22 Vadim R. Munirov , Nathaniel J. Fisch
‹ Prev 1 3 4 5 6 7 10 Next ›