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We study the properties of the turbulence driven by the magnetorotational instability (MRI) in a stratified shearing box with outflow boundary conditions and an equation of state determined by self-consistent dissipation and radiation…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Ji-Ming Shi , Julian H. Krolik , Shigenobu Hirose

By performing a global magnetohydrodynamical (MHD) simulation for the Milky Way with an axisymmetric gravitational potential, we propose that spatially dependent amplification of magnetic fields possibly explains the observed noncircular…

Astrophysics of Galaxies · Physics 2017-02-22 Takeru K. Suzuki , Yasuo Fukui , Kazufumi Torii , Mami Machida , Ryoji Matsumoto , Kensuke Kakiuchi

We show by numerical modeling that saturation of the population inversion reduces the stimulated thermal Rayleigh gain relative to the laser gain in large mode area fiber amplifiers. We show how to exploit this effect to raise mode…

Optics · Physics 2016-12-21 Arlee V. Smith , Jesse J. Smith

Cosmic rays (CRs) leave their sources mainly along the local magnetic field; in doing so they excite both resonant and nonresonant modes through streaming instabilities. The excitation of these modes leads to enhanced scattering and in turn…

High Energy Astrophysical Phenomena · Physics 2021-06-10 Benedikt Schroer , Oreste Pezzi , Damiano Caprioli , Colby Haggerty , Pasquale Blasi

Using the Berry-curvature modified kinetic equation we study instabilities in anisotropic chiral plasmas. It is demonstrated that even for a very small value of anisotropic parameter the chiral-imbalance instability is strongly modified.…

High Energy Physics - Theory · Physics 2014-09-09 Avdhesh Kumar , Jitesh R. Bhatt , P. K. Kaw

The growth of magneto-hydrodynamic fluctuations relevant to cosmic ray confinement in and near their sources, and the effects of local plasma conditions is revisited. We consider cases where cosmic rays penetrate a medium which may contain…

High Energy Astrophysical Phenomena · Physics 2021-02-10 B. Reville , G. Giacinti , R. Scott

Understanding the stability of the magnetic field in radiation zones is of crucial importance for various processes in stellar interior like mixing, circulation and angular momentum transport. The stability properties of a star containing a…

Solar and Stellar Astrophysics · Physics 2015-05-30 Alfio Bonanno , Vadim Urpin

The nonlinear development of streaming instabilities in the current layers formed during magnetic reconnection with a guide field is explored. Theory and 3-D particle-in-cell simulations reveal two distinct phases. First, the parallel…

Space Physics · Physics 2015-05-13 H. Che , J. F. Drake , M. Swisdak , P. H. Yoon

Numerical calculations and linear theory of radiation magnetohydrodynamic flows indicate that the photon bubble and magnetorotational instability (MRI) may produce large density inhomogeneities in radiation pressure supported media. We…

Astrophysics · Physics 2007-05-23 S. W. Davis , O. M. Blaes , N. J. Turner , A. Socrates

A new non-dissipative mechanism is proposed for the saturation of the axisymmetric magnetorotational (MRI) instability in thin Keplerian disks that are subject to an axial magnetic field. That mechanism relies on the energy transfer from…

Solar and Stellar Astrophysics · Physics 2015-06-11 Edward Liverts , Yuri Shtemler , Michael Mond , Orkan M. Umurhan , Dmitry V. Bisikalo

Cosmic ray acceleration through first-order Fermi acceleration in a collisionless plasma relies on efficient scattering off magnetic field fluctuations. Scattering is most efficient for magnetic field fluctuations with wavelengths on the…

High Energy Astrophysical Phenomena · Physics 2015-05-30 K. M. Schure , A. R. Bell

We report on the first experimental observation of a current-driven instability developing in a quasi-neutral matter-antimatter beam. Strong magnetic fields ($\geq$ 1 T) are measured, via means of a proton radiography technique, after the…

The magnetorotational instability (MRI) is thought to play a key role in the formation of stars and black holes by sustaining the turbulence in hydrodynamically stable Keplerian accretion discs. In previous experiments the MRI was observed…

The problem of the stability of magnetic fields in stars has a long history and has been investigated in detail in perturbation theory. Here we consider the nonlinear evolution of a non-rotating neutron star with a purely poloidal magnetic…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Riccardo Ciolfi , Samuel K. Lander , Gian Mario Manca , Luciano Rezzolla

Magnetic field amplification is needed to accelerate cosmic cays to PeV energies in supernova remants. Escaping cosmic rays trigger a return current in the plasma that drives a non-resonant hybrid instability. We run simulations in which we…

High Energy Astrophysical Phenomena · Physics 2012-09-17 K. M. Schure , A. R. Bell

Non-Abelian plasma instabilities play a crucial role in the nonequilibrium dynamics of a weakly coupled quark-gluon plasma and they importantly modify the standard perturbative bottom-up thermalization scenario in heavy-ion collisions.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Anton Rebhan , Michael Strickland , Maximilian Attems

We perform a linear magnetohydrodynamic perturbation analysis for a stratified magnetized envelope where the diffusion of heat is mediated by charged particles that are confined to flow along magnetic field lines. We identify an…

Astrophysics · Physics 2009-11-13 Aristotle Socrates , Ian J. Parrish , James M. Stone

It is shown that the transport in low temperature, collisional, bounded plasma is enhanced by instabilities at high magnetic field. While the magnetic field confines the electrons in a stable plasma, the instability completely destroys the…

Plasma Physics · Physics 2019-09-04 R. Lucken , A. Bourdon , M. Lieberman , P. Chabert

The self-modulation (SM) instability transforms a long charged particle bunch traveling in plasma into a train of microbunches that resonantly drives large-amplitude wakefields. We present the first determination of the saturation length of…

The influence of stable and unstable stratification on the amplification of coherent structures in turbulent channel flows is investigated by computing the linear response to stochastic forcing. The responses to momentum and thermal forcing…

Fluid Dynamics · Physics 2023-06-16 Carlo Cossu