Browsing by Subject "Instabilidade em plasmas"
Now showing items 1-20 of 25
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Análise numérica bi-dimensional para harmônicos eletrostáticos de ondas de Langmuir
(2018) [Thesis]Neste trabalho estudamos os harmonicos eletrostaticos de ondas de Langmuir em um plasma nao magnetizado e sem colisoes usando a teoria de turbulencia fraca (TTF). Primeiramente fazemos uma introducao a teoria de turbulencia ... -
Centroid motion in periodically focused beams
(2005) [Journal article]The role of the centroid dynamics in the transport of periodically focused particle beams is investigated. A Kapchinskij–Vladimirskij equilibrium distribution for an off-axis beam is derived. It is shown that centroid and ... -
Coherence–incoherence transition in nonlinear wave interactions
(2005) [Journal article]In this paper we analyze the transition from coherent to incoherent wave dynamics in a broad-band triplet interaction, where, in contrast to previous models, wave vector selection rules are imposed on the nonlinear terms ... -
Dinâmica não-linear da instabilidade feixe-plasma biodimensional
(2011) [Thesis]O presente trabalho desenvolve a abordagem bidimensional, tanto no espaço de velocidades como no espaço de número de onda, para determinar a evolução temporal dos modos eletrostáticos íon-sônico e de Langmuir, e das ... -
Efeitos de ondas do tipo cíclotron eletrônica sobre a evolução de instabilidades neoclássicas em tokamaks
(2016) [Dissertation]O tokamak é um dos mais promissores modelos de reatores de fusão. O mesmo consiste em um sistema de confinamento magnético de forma toroidal, onde coexistem um campo magnético toroidal gerado por bobinas externas e um campo ... -
Estudo da interação feixe-plasma como aplicação da teoria de turbulência em plasmas
(2014) [Dissertation]Neste trabalho estudamos a interação feixe-plasma aplicando a teoria de turbulência fraca. Primeiramente fazemos uma introdução `a teoria cinética de plasmas, estudando aspectos fundamentais como: a abordagem estatística ... -
Evolução de modos tipo tearing neoclássicos sob a ação da onda de cíclotron eletrônica
(2014) [Work completion of graduation]Este trabalho insere-se dentro de um esforço da comunidade científica mundial que visa contribuir para o entendimento e controle de fenômenos e processos que possam tornar viável o uso de fusão termonuclear como fonte ... -
Generation of harmonic Langmuir mode by beam-plasma instability
(2002) [Journal article]In this article, numerical solutions of the generalized weak turbulence equation [P. H. Yoon, Phys. Plasmas 7, 4858 (2000)] are carried out. In the generalized weak turbulence theory, the generation of the 2vpe-harmonic ... -
Influence of flavor oscillations on neutrino beam instabilities
(2014) [Journal article]We consider the collective neutrino plasma interactions and study the electron plasma instabilities produced by a nearly mono-energetic neutrino beam in a plasma. We describe the mutual interaction between neutrino flavor ... -
Instabilidade em plasmas espaciais e astrofísicos na presença de partículas de poeira com carga variável
(2016) [Thesis]O uso de uma descrição cinética para analisar a propagação de ondas eletromagnéticas em um plasma empoeirado (dusty plasma) vem sendo desenvolvido ao longo dos últimos anos. À medida que a teoria é desenvolvida, novas ... -
Instabilities and propagation of neutrino magnetohydrodynamic waves in arbitrary direction
(2017) [Journal article]In a previous work [Haas et al., Phys. Plasmas 23, 012104 (2016)], a new model was introduced, taking into account the role of the Fermi weak force due to neutrinos coupled to magnetohydrodynamic plasmas. The resulting ... -
Ion-cyclotron instability in plasmas described by product-bi-kappa distributions
(2015) [Journal article]The dispersion relation for parallel propagating waves in the ion-cyclotron branch is investigated numerically by considering that the velocity distribution of the ion population is a function of type product-bi-kappa. We ... -
Ion firehose instability in plasmas with plasma particles described by product bi-kappa distributions
(2014) [Journal article]We investigate the dispersion relation for low frequency electromagnetic waves propagating parallel to the ambient magnetic field, considering that the velocity distributions of ions and electrons can be either bi-Maxwellian ... -
Ionospheric ion-acoustic enhancements by turbulent counterstreaming electron beam-plasma interaction
(2010) [Journal article]Ion-acoustic enhancements are investigated within the context of turbulent beam-plasma interaction processes. The analysis assumes a pair of counterstreaming electron beams interacting with the background plasma. Two-dimensional ... -
Maser-beam instability of Bernstein waves
(2000) [Journal article]The present study constitutes a continuation and improvement of the preceding work by Yoon et al. [J. Geophys. Res. 104, 19801 (1999)]. In the present discussion, an instability of Bernstein waves excited by a beam of ... -
Mode coupling of low frequency electromagnetic waves in magnetized dusty plasmas
(2005) [Journal article]A kinetic description is used to analyze wave propagation in dusty plasmas, taking into account the fluctuation of the charge of the dust particles due to inelastic collisions with electrons and ions. The case of propagation ... -
Neutrino-driven electrostatic instabilities in a magnetized plasma
(2017) [Journal article]The destabilizing role of neutrino beams on the Trivelpiece-Gould modes is considered, assuming electrostatic perturbations in a magnetized plasma composed by electrons in a neutralizing ionic background, coupled to a ... -
Nonlinear development of weak beam-plasma instability
(2001) [Journal article]Nonlinear interactions of tenuous electron beam, background, unmagnetized plasma, and self-consistently generated Langmuir and ion-sound waves are analyzed in the framework of plasma weak turbulence kinetic theory. Full ... -
Plasma emission by nonlinear electromagnetic processes
(2015) [Journal article]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 ... -
Propagação e amplificação de ondas eletromagnéticas em plasmas supertérmicos magnetizados
(2019) [Thesis]A anisotropia de temperatura de elétrons e íons no Vento Solar é um fenômeno que evidencia o papel de processos não térmicos que ocorrem no sistema Sol-Vento-Solar-Magnetosfera Terrestre (SVSM). Distribuições com dispersões ...
