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Related papers: Realization of Bullard's disc dynamo

200 papers

We present simulations of isolated disc galaxies in a realistic environment performed with the Tree-SPMHD-Code Gadget-3. Our simulations include a spherical circum-galactic medium (CGM) surrounding the galactic disc, motivated by…

Astrophysics of Galaxies · Physics 2018-11-28 Ulrich P. Steinwandel , Marcus C. Beck , Alexander Arth , Klaus Dolag , Benjamin P. Moster , Peter Nielaba

We summarize recent 2D MHD simulations of line-driven stellar winds from rotating hot-stars with a dipole magnetic field aligned to the star's rotation axis. For moderate to strong fields, much wind outflow is initially along closed…

Astrophysics · Physics 2007-05-23 Stan Owocki , Asif ud-Doula

Well controlled and highly stable magnetic fields are desired for a wide range of applications in physical research, including quantum metrology, sensing, information processing, and simulation. Here we introduce a low-cost hybrid assembly…

Quantum Physics · Physics 2018-12-21 Frederick Hakelberg , Philip Kiefer , Matthias Wittemer , Tobias Schaetz , Ulrich Warring

We investigate a two-dimensional system of magnetic colloids with anisotropic geometry (rods) subjected to an oscillating external magnetic field. The structural and dynamical properties of the steady states are analyzed, by means of…

Soft Condensed Matter · Physics 2019-08-20 Jorge L. C. Domingos , Everton A. de Freitas , W. P. Ferreira

A 1.8 T dipole magnet using thin grain oriented silicon steel laminations has been constructed as a prototype for a muon synchrotron ramping at 400 Hz. Following the practice in large 3 phase transformers and our own Opera-2d simulations,…

Accelerator Physics · Physics 2012-08-27 D. J. Summers , L. M. Cremaldi , T. L. Hart , L. P. Perera , M. Reep , H. Witte , S. Hansen , M. L. Lopes , J. Reidy,

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

We report measurements of dynamo action in a new experimental setup, named Fury, based on the use of an anisotropic electrical conductivity. It consists in a copper rotor rotating inside a copper stator, electrically connected with a thin…

General Physics · Physics 2022-12-21 Thierry Alboussière , Franck Plunian , Marc Moulin

Millisecond pulsars are rather weakly-magnetized neutron stars which are thought to have been spun up by disc accretion, with magnetic linkage between the star and the disc playing a key role. Their spin history depends sensitively on…

Solar and Stellar Astrophysics · Physics 2013-10-28 L. Naso , W. Kluźniak , J. C. Miller

Dynamical magnetic levitation has attracted broad interest in the realm of physics and engineering. The stability analysis of such system is of great significance for practical applications. In this work, we investigate the stable magnetic…

Classical Physics · Physics 2025-07-11 Mingjun Fan , Jinyu Chen , Yongquan Ji , Long Li , Chichuan Ma , Yu-Han Ma

We present the first results from three-dimensional spherical shell simulations of magnetic dynamo action realized by turbulent convection penetrating downward into a tachocline of rotational shear. This permits us to assess several…

Astrophysics · Physics 2011-02-11 Matthew Browning , Mark S. Miesch , Allan Sacha Brun , Juri Toomre

Hydromagnetic stresses in accretion discs have been the subject of intense theoretical research over the past one and a half decades. Most of the disc simulations have assumed a small initial magnetic field and studied the turbulence that…

Astrophysics · Physics 2009-11-13 Anders Johansen , Yuri Levin

Presence of a hot corona above the accretion disc can have important consequences for the evolution of magnetic fields and the Shakura-Sunyaev (SS) viscosity parameter $\alpha$ in such a strongly coupled system. In this work, we have…

High Energy Astrophysical Phenomena · Physics 2024-10-22 Nishant K. Singh , Arunima Ajay , S R Rajesh

The evolution of an initially stellar dipole type magnetosphere interacting with an accretion disk is investigated using numerical ideal MHD simulations. The simulations follow several 1000 Keplerian periods of the inner disk. The initial…

Astrophysics · Physics 2008-11-26 Ch. Fendt

We numerically investigate the generation of a magnetic field in a protostellar disc via an $\alpha \Omega$-dynamo and the resulting magnetohydrodynamic (MHD) driven outflows. We find that for small values of the dimensionless dynamo…

High Energy Astrophysical Phenomena · Physics 2018-03-05 Sergei Dyda , Richard V. E. Lovelace , Galina V. Ustyugova , Alexander V. Koldoba , Ira Wasserman

Martin & Lubow (2017) found that an initially sufficiently misaligned low mass protoplanetary disc around an eccentric binary undergoes damped nodal oscillations of tilt angle and longitude of ascending node. Dissipation causes evolution…

Earth and Planetary Astrophysics · Physics 2019-10-02 Rebecca G. Martin , Stephen H. Lubow

We examined the effect of toroidal magnetic fields on a viscous gaseous disk around a central object under an advection dominated stage. We found self-similar solutions for radial infall velocity, rotation velocity, sound speed, with…

Astrophysics · Physics 2015-06-24 C. Akizuki , J. Fukue

We investigate the effect of rotating, triaxial halos on disk galaxies through an extensive set of numerical N-body simulations. Our simulations use a rigid potential field for the halos and bulges and collisionless particles for the disks.…

Astrophysics · Physics 2007-05-23 Jeremy L. Tinker , Barbara S. Ryden

A proof of principle experiment of Three-dimensional spiral beam injection scheme has been carried out. This injection scheme requires a strongly x-y coupled beam to meet magnetic field distribution through solenoid magnet fringe field. In…

In a previous work (Pichardo et al. 2005), we studied stable configurations for circumstellar discs in eccentric binary systems. We searched for "invariant loops": closed curves (analogous to stable periodic orbits in time-independent…

Astrophysics · Physics 2009-11-13 Barbara Pichardo , Linda S. Sparke , Luis A. Aguilar

The paper proposes the design of a tri-mode coupled coil which enables three modes of operation for inducing electromagnetic field, where the focal adjustment of the E field can be optimized. Methods: The setup consists of two identical…

Medical Physics · Physics 2018-03-28 Raunaq Pradhan , Xiaohua Feng , Zheng Yuanjin