Alfven Waves
Mostrando 1-12 de 22 artigos, teses e dissertações.
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1. Excitação de ondas de helicon e de Alfvén em tokamak TCABR / Excitation of Helicon and Alfvén waves in tokamak TCABR
The objective of this work is to investigate the excitation of waves in a plasma using an antenna and to analyse the Alfvén resonances found. The Alfvén antenna heating system of the TCABR tokamak was designed to heat the plasma due to resonances. As the diodes of the toroidal field had burned down we used cleaning discharges, with low toroidal magnetic fi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/04/2011
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2. Waves in magnetized dusty plasmas with variable charge on dust particles
We present results obtained in recent years for wave propagation in a magnetized dusty plasma, including variable charge of the dust particles, and using a kinetic approach. Two forms of the dielectric tensor are obtained, which can be used depending on the application to be done. This dielectric tensor is used in some applications, in order to study the imp
Publicado em: 2011
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3. Determination fo the configuration of excited Alfvén waves in tokamak TCABR / Determinação da configuração de ondas de alfvén excitadas no tokamak TCABR
In order to enhance the efficiency of the TCABRs Alfvén waves heating system, called AWES - Alfvén Waves Excitement System a diagnostics for determining the radio-frequency power applied to the plasma and a processing circuit for the magnetic coil system was built, characterized, installed and put into operation. The RF diagnostics system was designed to d
Publicado em: 2007
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4. Simulação numérica da intermitência alfvência na heliosfera na presença de ruído / Numerical simulation of alfvénic intermittency in heliosphere in the presence of noise
O estudo da intermitencia e caos é necessário para o entendimento dos processos físicos fundamentais na relação Sol-Terra, onde a presençaa de múltiplos estados estacionários pode gerar uma dinâmica complexa se houver fontes estocásticas. O objetivo deste trabalho é aplicar a teoria de caos para investigar a natureza intermitente do ambiente Helio
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/02/2006
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5. Simulação numérica da intermitência alfvência na heliosfera na presença de ruído / Numerical simulation of alfvénic intermittency in heliosphere in the presence of noise
The study of intermittency and chaos is necessary for our understanding of the complex physical processes governing the Sun-Earth relation, where the presence of multiple steady states can lead to complex dynamics if there is a stocastic source. The objective of this work is to apply the chaos theory to investigate the intermittent nature of the heliospheric
Publicado em: 2006
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6. Theory and computer modelling of Alfvén wave heating in TCABR Tokamak / "Teoria e modelamento computacional de aquecimento de plasma por ondas de alfvén no tokamak TCABR"
In this work we present the study of the determination the best regimes and parameters¶for the heating experiments and current generation and plasma flow in the tokamak TCABR. Study of effects of plasma rotation in low frequency (LF), field penetration, absorption and ponderomotive forces in Tokamak Chauffage Alfvén Brésilien (TCABR)is investigated wi
Publicado em: 2006
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7. Simulação numérica da intermitência alfvência na heliosfera na presença de ruído / Numerical simulation of alfvénic intermittency in heliosphere in the presence of noise
O estudo da intermitencia e caos é necessário para o entendimento dos processos físicos fundamentais na relação Sol-Terra, onde a presençaa de múltiplos estados estacionários pode gerar uma dinâmica complexa se houver fontes estocásticas. O objetivo deste trabalho é aplicar a teoria de caos para investigar a natureza intermitente do ambiente Helio
Publicado em: 2006
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8. "Dusty Plasmas: stellar winds and the interstellar medium" / "Plasmas empoeirados: ventos estelares e o meio interestelar"
In this work, we firstly discuss the propagation of Alfvén waves in dusty plasmas found in several astrophysical environments. The wave dispersion relation is modified giving rise to new damping mechanisms. There are in the literature observational data indicating the presence of dust near the surface of cool giant and supergiant stars. We developed a stell
Publicado em: 2005
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9. Identification of the Alfvén wave resonances in the TCABR tokamak by the microwave reflectometry
The experimental results on the Alfvén mode structure identification by the microwave reflectometry in TCABR tokamak are presented. The knowledge of the spatial spectrum of the excited waves is crucial for optimization of Alfvén wave plasma heating and noninductive current drive scenarios in tokamak plasmas. No less important is the possibility to use the
Brazilian Journal of Physics. Publicado em: 2004-12
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10. Parallel permittivity elements for radio frequency waves in elongated D-shaped tokamaks
Parallel permittivity elements are derived for radio-frequency waves in an axisymmetric tokamak with D-shaped transverse cross-sections of the magnetic surfaces under arbitrary aspect ratio, arbitrary elongation and small triangularity. The bounce resonances are taken into account for untrapped (passing or circulating) and three groups of trapped particles.
Brazilian Journal of Physics. Publicado em: 2004-12
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11. The analysis of Alfvén wave antenna implementation in the ETE spherical tokamak
The preliminary design study of the Alfvén wave system for the ETE spherical tokamak is presented. The main objective of the proposed RF system is generation of travelling Alfvén waves, which can be used for the study of the non-inductive current drive and the plasma heating in a wide range of operational regimes, which are specific for tokamaks with small
Brazilian Journal of Physics. Publicado em: 2004-12
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12. Influence of the solar and density perturbations on the neutrino parameters
There are reasons to believe that the solar matter density fluctuates around an equilibrium profile. One of these reasons is a resonance between the Alfvén waves and the g-modes inside the Sun that creates spikes in the density profile. The neutrinos are created in the solar core and passing through these spikes feel them as a noisy perturbation, whose corr
Brazilian Journal of Physics. Publicado em: 2004-12