Navegação por Assunto "Plasmas"
Resultados 21-40 de 48
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Improving regular acceleration in the nonlinear interaction of particles and waves
(1995) [Artigo de periódico]In this work one studies the effects arising from the inclusion of a stationary extraordinary mode in the resonant interaction of magnetized particles and perpendicularly propagating electrostatic waves. It is found that ... -
Influence of wave dispersion on the self-consistent dynamics of cyclotron-laser-type systems
(1993) [Artigo de periódico]In this work, we make use of a Hamiltonian formalism to analyze the wave-particle dynamical interaction that takes place in cyclotronic systems. It is shown that the usual model of test particles moving in externally given ... -
Instabilidade eletrostáticas ocasionadas por feixes de íons em plasmas
(1979) [Tese]Analisam-se as instabilidades eletrostáticas ocasiona das pela injeção de um feixe de íons num plasma magnetizado, in finito, homogé- neo e sem colisões, como um possível mecanismo de aquecimento do plasma. A direção do ... -
Ion acoustic solitons in dense magnetized plasmas with nonrelativistic degenerate electrons and positrons
(2014) [Artigo de periódico]The propagation of electrostatic waves in a densemagnetized electron–positron–ion (EPI) plasma with nonrelativistic and ultrarelativistic degenerate electrons and positrons is investigated. The linear dispersion relation ... -
Length scale, quasiperiodicity, resonances, separatrix crossings, and chaos in the weakly relativistic Zakharov equations
(1995) [Artigo de periódico]Nonlinear saturation of unstable solutions to the weakly relativistic, one-dimensional Zakharov equations is considered in this paper. In order to perform the analysis, two quantities are introduced. One of them, p* is ... -
Modos de Case-van Kampen em plasmas quânticos descritos pelo Sistema de Wigner-Poisson
(2021) [Dissertação]São deduzidos modos de Case-van Kampen para sistemas quânticos governados pelo sistema de Wigner-Poisson. Começamos fazendo uma revisão de diferentes tratamentos matemáticos para o sistema de Vlasov-Poisson, viz., o ... -
Nonintegrable dynamics of the triplet-triplet spatiotemporal interaction
(1999) [Artigo de periódico]In this paper we examine the coupling of two wave triplets sharing two common modes. The analysis is performed in the solitonic sector of the parameter space where uncoupled solutions departing from linearly unstable ... -
Nonlinear evolution of beam-plasma instability in inhomogeneous medium
(2011) [Artigo de periódico]The problem of electron-beam propagation in inhomogeneous solar wind is intimately related to the solar type II and/or type III radio bursts. Many scientists have addressed this issue in the past bymeans of quasi-linear ... -
Ondas e instabilidades em plasmas com inomogeneidades suaves na densidade e no campo magnético de equilíbrio
(2003) [Tese]No presente trabalho, estudamos a absorção e amplificação de ondas eletromagnéticas que se propagam em plasmas com densidade e temperatura fracamente inomogêneas, imersos em um campo magnético também inomogêneo, tendo como ... -
On the Onsager symmetry of the effective dialetric tensor for plasmas in inhomogeneous magnetic field
(2004) [Artigo de periódico] -
Particle acceleration by large-amplitude waves revisited
(1997) [Artigo de periódico]We reconsider the problem of particle acceleration by large-amplitude electromagnetic waves. We make use of a fully relativistic Hamiltonian formalism to show that, as opposed to nonelativistic results obtained by Kuo and ... -
Particle-in-cell and weak turbulence simulations of plasma emission
(2019) [Artigo de periódico]The plasma emission process, which is the mechanism for solar type II and type III radio burst phenomena, is studied by means of particle-in-cell (PIC) and weak turbulence (WT) simulation methods. “Plasma emission” is meant ... -
Plasma emission by counter-streaming electron beams
(2016) [Artigo de periódico]The radiation emission mechanism responsible for both type-II and type-III solar radio bursts is commonly accepted as plasma emission. Recently Ganse et al. suggested that type-II radio bursts may be enhanced when the ... -
Plasma emission by nonlinear electromagnetic processes
(2015) [Artigo de periódico]The plasma emission, or electromagnetic (EM) radiation at the plasma frequency and/or its harmonic(s), is generally accepted as the radiation mechanism responsible for solar type II and III radio bursts. Identification and ... -
Plasmas: o que são e onde estão
(2009-07-30) [Vídeo]O especial Física na Cultura exibe a palestra "Plasmas: o que são e onde estão", que apresenta e ocorrência desse que é considerado o quarto estado da matéria e as suas principais aplicações em processos tecnológicos. -
Propagação de ondas eletromagnéticas não lineares em plasmas de múltiplas espécies
(1988) [Tese]Neste trabalho analisamos a propagaçãode ondas eletro magnéticas não lineares em plasmas constituídos por três espécies de partículas, considerando dois casos distintos. No primeiro estudamos a propagação de ondas eletrostá ... -
Pulsos elétricos em cavidades ressonantes retangulares plasmônicas
(2015) [Trabalho de conclusão de graduação]Cavidades Ressonantes são guias de ondas perfeitamente fechadas por paredes metálicas. Sua tecnologia con na a energia eletromagnética em um padrão de ondas eletromagnéticas estacionárias com frequências bem de nidas e, ... -
Quasilinear analysis of loss-cone driven weakly relativistic electron cyclotron maser instability
(1995) [Artigo de periódico]This paper presents a quasilinear analysis of the relativistic electron cyclotron maser instability. Two electron popUlations are assumed: a low-temperature background component and a more energetic loss-cone population. ... -
Quasilinear evolution of cyclotron maser instability
(1995) [Artigo de periódico]A quasilinear analysis of the relativistic electron cyclotron maser instability is presented. A background plasma is assumed to support the wave motion, while the instability is driven by a tenuous population of energetic ... -
Self-consistent chaos and Arnold diffusion in a cyclotron-maser wave-particle system
(1995) [Artigo de periódico]In this work, we search for the presence of chaos in a self-consistent model for the cyclotronresonance maser accelerator. Two characteristic regimes are identified. If the initial action variable of the accelerating ...