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Related papers: The $\alpha$ Dynamo Effects in Laboratory Plasmas

200 papers

For cylindrical differentially rotating plasmas, we study large-scale magnetic field generation from finite amplitude non-axisymmetric perturbations by comparing numerical simulations with quasi-linear analytic theory. When initiated with a…

High Energy Astrophysical Phenomena · Physics 2016-10-31 F. Ebrahimi , E. G. Blackman

Our attention focuses on the stochastic dynamo equation with non-normal operator that give an insight into the role of stochastics and non-normality in the galactic magnetic field generation. The main point of this Letter is a discussion of…

Astrophysics · Physics 2009-11-07 Sergei Fedotov

It is found that the Lorentz force generated by the magnetic drift drives a generic plasma pinch fluxes of particle, energy and momentum through the Stokes-Einstein relation. The proposed theoretical model applies for both electrons and…

Plasma Physics · Physics 2016-08-24 Shaojie Wang

We analyze direct numerical simulations of large-scale dynamos in inhomogeneous nonhelically driven rotating turbulence with and without shear. The forcing is modulated so that the turbulent intensity peaks in the middle of the…

Plasma Physics · Physics 2025-05-02 Axel Brandenburg , Ethan T. Vishniac

We generalise the theory of mean-field galactic dynamos by allowing for temporal non-locality in the mean electromotive force (emf). This arises in random flows due to a finite response time of the mean emf to changes in the mean magnetic…

Astrophysics of Galaxies · Physics 2015-06-05 Luke Chamandy , Kandaswamy Subramanian , Anvar Shukurov

We analyze the linear stability of a dilute, hot plasma, taking into account the effects of stratification and anisotropic thermal conduction. The work is motivated by attempts to understand the dynamics of the intracluster medium in galaxy…

High Energy Astrophysical Phenomena · Physics 2010-08-04 Steven A. Balbus , Christopher S. Reynolds

It is shown that ambipolar diffusion as a toy nonlinearity leads to very similar behaviour of large scale turbulent dynamos as full MHD. This is demonstrated using both direct simulations in a periodic box and a closure model for the…

Astrophysics · Physics 2007-05-23 Axel Brandenburg , Kandaswamy Subramanian

The self-diffusion phenomenon in a two-dimensional dusty plasma at extremely strong (effective) magnetic fields is studied experimentally and by means of molecular dynamics simulations. In the experiment the high magnetic field is…

The axisymmetric 3-D MHD outflow of a cold plasma from a magnetized and rotating astrophysical object is numerically simulated with the purpose of investigating the outflow's magnetocentrifugal acceleration and eventual collimation. Gravity…

Astrophysics · Physics 2009-10-31 S. Bogovalov , K. Tsinganos

Small magnetic fluctuations ($B_1/B_0 \sim 10^{-4}$) are intrinsically present in a magnetic confinement plasma due to turbulent currents. While the perpendicular transport of particles and heat is typically dominated by fluctuations of the…

Plasma Physics · Physics 2025-01-10 Kaiyu Zhang , Wladimir Zholobenko , Andreas Stegmeir , Konrad Eder , Frank Jenko

Helicity and \alpha effect driven by the nonaxisymmetric Tayler instability of toroidal magnetic fields in stellar radiation zones are computed. In the linear approximation a purely toroidal field always excites pairs of modes with…

Solar and Stellar Astrophysics · Physics 2015-05-28 G. Ruediger , L. L. Kitchatinov , D. Elstner

To power gamma-ray bursts and other high-energy events, large-scale magnetic fields are required to extract rotational energy from compact objects such as black holes and neutron stars. The magnetorotational instability (MRI) is a key…

High Energy Astrophysical Phenomena · Physics 2025-09-17 Alexis Reboul-Salze , Loren E. Held , Kenta Kiuchi

Magnetic holes have been frequently observed in the magnetosheath of Earth and it is believed that these structures are the result of nonlinear evolution of mirror instability. Mirror mode fluctuations mostly appear as magnetic holes in…

Space Physics · Physics 2017-04-04 Narges Ahmadi , Kai Germaschewski , Joachim Raeder

The existence of large-scale dynamos in rigidly rotating turbulent convection without shear is studied using three-dimensional numerical simulations of penetrative rotating compressible convection. We demonstrate that rotating convection in…

Astrophysics · Physics 2011-02-11 P. J. Käpylä , M. J. Korpi , A. Brandenburg

Fluctuation dynamos provide a robust mechanism for amplifying weak seed magnetic fields in turbulent astrophysical plasmas. However, their behaviour in the highly compressible regimes characteristic of the interstellar medium remains…

Astrophysics of Galaxies · Physics 2026-02-18 Ameya Uday Nagdeo , Sharanya Sur , Bhargav Vaidya

Plasmas are beset with instabilities of all types, hydrodynamic, magneto-hydrodynamic, and electromagnetic. These instabilities are complex, occur over a large range of temporal and spatial scales, are most often unmanageable, and have…

Many astrophysical systems encompass very large dynamical ranges in space and time, which are not accessible by direct numerical simulations. Thus, idealized subvolumes are often used to study small-scale effects including the dynamics of…

Fluid Dynamics · Physics 2018-05-23 Philipp Grete , Brian W. O'Shea , Kris Beckwith

Using the magnetohydrodynamic (MHD) description, we develop a nonlinear dynamo model that couples the evolution of the large scale magnetic field with turbulent dynamics of the plasma at small scale by electromotive force (e.m.f.) in the…

Earth and Planetary Astrophysics · Physics 2011-09-29 Giuseppina Nigro , Pierlugi Veltri

We are concerned with large scale magnetic field dynamo generation and propagation of magnetic fronts in turbulent electrically conducting fluids. An effective equation for the large scale magnetic field is developed here that takes into…

Astrophysics · Physics 2009-11-06 Sergei Fedotov , Alexey Ivanov , Andrey Zubarev

It is known that a plasma in a magnetic field, conceived microscopically as a system of point charges, can exist in a magnetized state, and thus remain confined, inasmuch as it is in an ordered state of motion, with the charged particles…

Mathematical Physics · Physics 2015-06-04 A. Carati , M. Zuin , A. Maiocchi , M. Marino , E. Martines , L. Galgani