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Related papers: Dispersion Equation for Smith-Purcell FEL

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We solve the linearized gyrokinetic equation, quasineutrality condition, and Ampere's law to obtain the dispersion relation of microtearing modes (MTMs) in collisionless low-beta toroidal plasmas. Consistent with past studies, we find that…

Plasma Physics · Physics 2024-02-28 Benjamin D. G. Chandran , Alexander A. Schekochihin

We reconsider the radial Saffman-Taylor instability, when a fluid injected from a point source displaces another fluid with a higher viscosity in a Hele-Shaw cell, where the fluids are confined between two neighboring flat plates. The…

Fluid Dynamics · Physics 2014-12-09 Mathias Nagel , François Gallaire

A dispersion equation, which describes the interaction of low density electron beam with a degenerate electron quantum plasma, is derived and examined for some interesting cases. In addition to the instabilities similar to those for…

Plasma Physics · Physics 2015-05-14 Levan N. Tsintsadze , Nodar L. Tsintsadze

A Particle-in-Cell (PIC) numerical simulation of the electron Weibel instability is applied in a frame of Darwin (radiationless) approximation of the self-consistent fields of sparse plasma. As a result, we were able to supplement the…

Plasma Physics · Physics 2010-06-29 L. V. Borodachev , D. O. Kolomiets

We explore various models for the pattern forming instability in a laser-driven cloud of cold two-level atoms with a plane feedback mirror. Focus is on the combined treatment of nonlinear propagation in a diffractively thick medium and the…

Atomic Physics · Physics 2016-06-16 W. J. Firth , I. Krešić , G. Labeyrie , A. Camara , P. Gomes , T. Ackemann

We study modulational instability in a fiber system resembling a dispersion-managed link where the sign of the group-velocity dispersion varies randomly according to a telegraph process. We find that the instability gain of stochastic…

Optics · Physics 2023-11-13 Andrea Armaroli , Matteo Conforti

The Smith-Purcell radiation is usually measured when an electron passes over the grating of metallic stripes. However, for high frequencies (exceeding the plasma frequency of the grating material) none material could be treated as a…

Accelerator Physics · Physics 2014-11-21 N. F. Shul'ga , V. V. Syshchenko

We show that the dispersion relation for gradient-drift and Farley-Buneman instabilities within the approximation of the two-fluid MHD should contain the terms which are traditionally supposed to be small. These terms are caused by taking…

Plasma Physics · Physics 2010-04-13 O. I. Berngardt , A. P. Potekhin

The stimulated Raman scattering instability in a fully degenerate electron plasma is studied applying relativistic hydrodynamic and Maxwell equations. We demonstrated that the instability develops for weakly as well as strongly relativistic…

Plasma Physics · Physics 2017-08-02 G. T. Chanturia , V. I. Berezhiani , S. M. Mahajan

Dispersion equations are a common paradigm of collective excitation physics. However, in some systems, dispersion equations contain multivalued functions and their solutions are ambiguous. As an example, we consider graphene on a polar…

Mesoscale and Nanoscale Physics · Physics 2024-12-09 S. M. Kukhtaruk , V. A. Kochelap

Thermal energy atom scattering at a surface with grazing incidence conditions is an innovative method for investigating dispersive atom-surface interactions with potential application in quantum sensing interferometry. The complete…

Atomic Physics · Physics 2024-07-16 Lee Yeong Kim , Do Won Kang , Jong Chan Lee , Eunmi Chae , Wieland Schöllkopf , Bum Suk Zhao

The numerical instability observed in the Electromagnetic-Particle-in-cell (EM-PIC) simulations with a plasma drifting with relativistic velocities is studied using both theory and computer simulations. We derive the numerical dispersion…

We present an algorithm for solving the linear dispersion relation in an inhomogeneous, magnetised, relativistic plasma. The method is a generalisation of a previously reported algorithm that was limited to the homogeneous case. The…

Astrophysics · Physics 2009-11-13 J. Pétri , J. G. Kirk

We predict and study the quantum-electrodynamical effect of parametric self-induced excitation of a molecule moving above the dielectric or conducting medium with periodic grating. In this case the radiation reaction force modulates the…

Quantum Physics · Physics 2016-09-08 Alexey Belyanin , Federico Capasso , Vitaly Kocharovsky , Vladimir Kocharovsky

The spreading of a thin film of suspension on a spinning disk and the accompanying contact line instability is studied through flow visualization experiments. The critical radius for the onset of instability shows an increase with increase…

Soft Condensed Matter · Physics 2016-06-10 Mayuresh Kulkarni , Subhadarshinee Sahoo , Pankaj Doshi , Ashish V. Orpe

We have calculated the general dispersion relationship for surface waves on a ferrofluid layer of any thickness and viscosity, under the influence of a uniform vertical magnetic field. The amplification of these waves can induce an…

Fluid Dynamics · Physics 2009-10-30 Berengere Abou , Gilles Neron de Surgy , Jose-Eduardo Wesfreid

The spectral problem is studied associated with Maxwell-Boltzmann equations describing collisionless plasma. Formula for instability index is obtained and effective conditions of two-stream instability are given.

Spectral Theory · Mathematics 2019-03-06 Stanislav Stepin

We consider a beam-string-beam transmission problem, where two structurally damped or undamped beams are coupled with a frictionally damped string by transmission conditions. We show that for this type of structure, the dissipation produced…

Analysis of PDEs · Mathematics 2021-08-17 Bienvenido Barraza Martínez , Jairo Hernández Monzón , Gustavo Vergara Rolong

The filamentation instability (sometimes also referred to as "Weibel") is a key process in many astrophysical scenario. In the Fireball model for Gamma Ray Bursts, this instability is believed to mediate collisionless shock formation from…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Antoine Bret , Erica Perez Alvaro

Turbulent relative dispersion is studied theoretically with a focus on the evolution of probability distribution of the relative separation of two passive particles. A finite separation speed and a finite correlation of relative velocity,…

Chaotic Dynamics · Physics 2007-05-23 Takeshi Ogasawara , Sadayoshi Toh