Navegação Ciências Exatas e da Terra por Autor "Gaelzer, Rudi"
Resultados 21-40 de 41
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Oblique Alfvén waves in a stellar wind environment with dust particles charged by inelastic collisions and by photoionization
(2022) [Artigo de periódico]The characteristics of Alfvén waves propagating in a direction oblique to the ambient magnetic field in a stellar wind environment are discussed. A kinetic formulation for a magnetized dusty plasma is adopted considering ... -
Obliquely propagating electromagnetic waves in magnetized kappa plasmas
(2016) [Artigo de periódico]Velocity distribution functions (VDFs) that exhibit a power-law dependence on the high-energy tail have been the subject of intense research by the plasma physics community. Such functions, known as kappa or superthermal ... -
On the dimensionally correct kinetic theory of turbulence for parallel propagation
(2015) [Artigo de periódico]Yoon and Fang [Phys. Plasmas 15, 122312 (2008)] formulated a second-order nonlinear kinetic theory that describes the turbulence propagating in directions parallel/anti-parallel to the ambient magnetic field. Their theory ... -
On the influence of the shape of kappa distributions of ions and electrons on the ioncyclotron instability
(2017) [Artigo de periódico]The dispersion relation for ion-cyclotron waves propagating along the direction of the ambient magnetic field is investigated numerically by considering different forms of kappa functions as velocity distributions of ions ... -
On the Onsager symmetry of the effective dialetric tensor for plasmas in inhomogeneous magnetic field
(2004) [Artigo de periódico] -
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 ... -
Particle-in-cell simulations on spontaneous thermal magnetic field fluctuations
(2013) [Artigo de periódico]In this paper an electromagnetic particle code is used to investigate the spontaneous thermal emission. Specifically we perform particle-in-cell simulations employing a non-relativistic isotropic Maxwellian particle ... -
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 ... -
Plasma emission by weak turbulence processes
(2014) [Artigo de periódico]The plasma emission is the radiation mechanism responsible for solar type II and type III radio bursts. The first theory of plasma emission was put forth in the 1950s, but the rigorous demonstration of the process based ... -
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 ... -
Solar wind strahl broadening by self-generated plasma waves
(2013) [Artigo de periódico]This Letter reports on the results of numerical simulations which may provide a possible explanation for the strahl broadening during quiet solar conditions. The relevant processes involved in the broadening are due to ... -
Spontaneous emission of electromagnetic radiation in turbulent plasmas
(2014) [Artigo de periódico]Known radiation emission mechanisms in plasmas include bremmstrahlung (or free-free emission), gyro- and synchrotron radiation, cyclotron maser, and plasma emission. For unmagnetized plasmas, only bremmstrahlung and plasma ... -
The dispersion relation for eletrostatic fluctuations in weakly inhomogeneous plasmas
(2004) [Artigo de periódico] -
The effective longitudinal dielectric constant for plasmas in inhomogeneous magnetic fields
(2004) [Artigo de periódico] -
The general dielectric tensor for bi-kappa magnetized plasmas
(2016) [Artigo de periódico]In this paper, we derive the dielectric tensor for a plasma containing particles described by an anisotropic superthermal (bi-kappa) velocity distribution function. The tensor components are written in terms of the ... -
The oblique firehose instability in a bi-kappa magnetized plasma
(2018) [Artigo de periódico]In this work, we derive a dispersion equation that describes the excitation of the oblique (or Alfvén) firehose instability in a plasma that contains both electron and ion species modelled by bi-kappa velocity distribution ... -
Transition from thermal to turbulent equilibrium with a resulting electromagnetic spectrum
(2014) [Artigo de periódico]A recent paper [Ziebell et al., Phys. Plasmas 21, 010701 (2014)] discusses a new type of radiation emission process for plasmas in a state of quasi-equilibrium between the particles and enhanced Langmuir turbulence. Such ... -
Two dimensional kinetic analysis of electrostatic harmonic plasma waves
(2016) [Artigo de periódico]Electrostatic harmonic Langmuir waves are virtual modes excited in weakly turbulent plasmas, first observed in early laboratory beam-plasma experiments as well as in rocket-borne active experiments in space. However, their ... -
Unified formulation for inhomogeneity-driven instabilities in the lower-hybrid range
(2002) [Artigo de periódico]A local dispersion relation that describes inhomogeneity-driven instabilities in the lower-hybrid range is derived following a procedure that correctly describes energy exchange between waves and particles in inhomogeneous ...
