Navegação Ciências Exatas e da Terra por Assunto "Física de plasmas"
Resultados 1-20 de 23
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Adiabatic-nonadiabatic transition in warm long-range interacting systems : the transport of intense inhomogeneous beams
(2012) [Artigo de periódico]We investigate the role of the temperature in the onset of singularities and the consequent breakdown in a macroscopic fluid model for long-range interacting systems. In particular, we consider an adiabatic fluid description ... -
Analytical method for determining at equilibrium the envelope and emittance of initially mismatched beams
(2009) [Artigo de periódico]This work presents a fully analytic way of determining relevant equilibrium quantities of a high-intensity charged particle beam submitted to magnetic focusing while inside a linear channel. Through the current approach, ... -
An analytical model to determine equilibrium quantities of azimuthally symmetric and mismatched charged particle beams under linear focusing
(2008) [Artigo de periódico]The model developed here analytically allows to obtain equilibrium quantities of interest from high-intensity charged particle beams such as the emittance, beam envelope, and the number of beam halo particles. The results ... -
Bernstein–Greene–Kruskal and Case–Van Kampen Modes for the Landau–Vlasov Equation
(2022) [Artigo de periódico]The one-dimensional Landau–Vlasov equation describing ultracold dilute bosonic gases in the mean-field collisionless regime under strong transverse confinement is analyzed using traditional methods of plasma physics. ... -
Centroid motion in periodically focused beams
(2005) [Artigo de periódico]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 ... -
Controlling chaos in wave-particle interactions
(2012) [Artigo de periódico]We analyze the behavior of a relativistic particle moving under the influence of a uniform magnetic field and a stationary electrostatic wave. We work with a set of pulsed waves that allows us to obtain an exact map for ... -
Dielectric tensor for inhomogeneous plasmas in inhomogeneous magnetic field
(1999) [Artigo de periódico]The derivation of explicit expressions for the effective dielectric tensor to be utilized in the dispersion relation for weakly inhomogeneous plasmas is discussed. The general expressions obtained are useful for situations ... -
Dispersive effects on the main wave modulational instability in free electron lasers
(1990) [Artigo de periódico]The main-wave one-dimensional modulational instability due to the dispersive terms of the wave equation in a free-electron laser is introduced and analyzed. We derive the appropriate dispersion relation and compare its ... -
Effects of dust charge variation on electrostatic waves in dusty plasmas with temperature anisotropy
(2009) [Artigo de periódico]We utilize a kinetic approach to the problem of wave propagation in dusty plasmas, taking into account the variation of the charge of the dust particles due to inelastic collisions with electrons and ions. The components ... -
Intrinsic modulational alfvenic turbulence
(1997) [Artigo de periódico]The nonlinear dynamics of a nite-amplitude Alfv en wave in a dispersive modulational regime is analysed. Use is made of a conservative model to show that turbulence may arise via deterministic chaos. The behaviour of the ... -
Ionospheric ion-acoustic enhancements by turbulent counterstreaming electron beam-plasma interaction
(2010) [Artigo de periódico]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 ... -
Mode coupling of low frequency electromagnetic waves in magnetized dusty plasmas
(2005) [Artigo de periódico]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 ... -
A new formulation for the dielectric tensor for magnetized dusty plasmas with variable charge on the dust particles
(2008) [Artigo de periódico]A kinetic approach to the problem of wave propagation in dusty plasmas, which takes into account the variation of the charge of the dust particles due to inelastic collisions with electrons and ions, is utilized as a ... -
Numerical simulation of a negative ion plasma expansion into vacuum
(1997) [Artigo de periódico]The expansion into vacuum of a one-dimensional, collisionless, negative ion plasma is investigated in the framework of the Vlasov–Poisson model. The basic equations are written in a ‘‘new time space’’ by use of a rescaling ... -
Observation of deterministic chaos in electrical discharges in gases
(1987) [Artigo de periódico]We report that dc-excited discharges in gases display current oscillations which develop into deterministically chaotic behavior. A period-doubling route to chaos characteristic of 1D maps is established for sealed discharges ... -
Off-axis stability of intense continuous relativistic beams
(2009) [Artigo de periódico]This paper investigates the stability of off-axis continuous intense relativistic beams propagating inside a circular conducting pipe. The equations of motion for the centroid and the envelope of slightly off-axis beams ... -
Quasistationary trajectories of the mean-field XY Halmitonian model : a topological perspective
(2005) [Artigo de periódico]We employ a topological approach to investigate the nature of quasistationary states of the mean-field XY Hamiltonian model. We focus on the quasistationary states reached when the system is initially prepared in a fully ... -
Relaxation of intense inhomogeneous charged beams
(2009) [Artigo de periódico]This work analyzes the dynamics of inhomogeneous, magnetically focused high intensity beams of charged particles. Initial inhomogeneities lead to density waves propagating transversely in the beam core, and the presence ... -
Simulation of asymmetric solar wind electron distributions
(2009) [Artigo de periódico]The electron distributions detected in the solar wind feature varying degrees of anisotropic high-energy tail. In a recent work the present authors numerically solved the one-dimensional electrostatic weak turbulence ... -
Standard map in magnetized relativistic systems : fixed points and regular acceleration
(2010) [Artigo de periódico]We investigate the concept of a standard map for the interaction of relativistic particles and electrostatic waves of arbitrary amplitudes, under the action of external magnetic fields. The map is adequate for physical ...
