Formation of vortex chains in a nonuniform magnetized electron plasma

Shukła, P. K.; Srinivas, J.; Murtaza, G.; Saleem, H.

doi:10.1063/1.870927

Cited by 5 publications

(11 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…4 The dynamics of electron plasma vortices in background vorticity distribution has been investigated both analytically and numerically 4 as well as experimentally. 7,9,10 Vortex structures have been observed [11][12][13] in low-temperature laboratory devices in which electron clouds are confined by dc electric and magnetic fields. 7 Possible stationary solutions of the latter can be cast in the form of a global vortex pattern 7,8 and a double vortex.…”

Section: Introductionmentioning

confidence: 99%

Turbulence and transport in two-dimensional magnetized electron plasmas

Shaikh

Shukła

2008

Physics of Plasmas

Self Cite

View full text Add to dashboard Cite

Electron plasmas confined by an external magnetic field exhibit variations in a two-dimensional plane orthogonal to the confining magnetic field. A nonlinear fluid simulation code to investigate the properties of 2-D electron plasma wave turbulence in a nonuniform magnetoplasma has been developed. It is found that the presence of the density gradient convection by mean electric fields considerably influence the characteristic nonlinear interaction processes, such as the energy cascades and the cross-field electron transport. The initial random turbulent state evolves towards an intermittent state where forward cascade of vorticity coexists with an inverse cascade of electric potential fluctuations. The latter lead to the formation of large scale entities in 2D electron plasmas and can be alternatively understood by seeking exact nonlinear coherent vortex solutions in the form of a dipolar-like configuration. The energy cascades are governed typically by the Kolmogorov-like $k^{-5/3}$ spectrum. In agreement with the experimental observations, we find that the electron transport is improved significantly by the application of an externally imposed electric field

show abstract

Section: Introductionmentioning

confidence: 99%

Turbulence and transport in two-dimensional magnetized electron plasmas

Shaikh

Shukła

2008

Physics of Plasmas

Self Cite

View full text Add to dashboard Cite

show abstract

“…͑8͒ can be reduced to the ‫ץ‬ z =0 limit of a previously reported set of equations. 18 By using Eqs. ͑1͒ and ͑2͒, and assuming B 0 = const, the governing equation ͑8͒ is reduced to…”

Section: Basic Equationmentioning

confidence: 99%

“…23 It has been shown that the governing nonlinear equations admit stationary solutions in the form of double [19][20][21][22]24 and global vortices 22 and a vortex chain. 18 In the present paper, the formation of vortical structures in a weakly non-neutral electron-ion magnetoplasma is investigated in the medium-frequency regime pi , ci Ӷ Ӷ c , where pi is the ion plasma frequency and ci ͑ c ͒ is the ion ͑electron͒ gyrofrequency. The plasma is non-neutral due to the presence of an unshielded electron population.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Vortex formation in an electron plasma with a sheared flow

Hall

Shukla

2005

Physics of Plasmas

Self Cite

View full text Add to dashboard Cite

The formation of vortex structures in an electron plasma with a sheared flow is investigated. The electron fluid is drifting in a self-electric field generated by an unshielded electron population. This setting is linearly unstable and an instability of diocotron (slipping-stream) type occurs. The time scale of the dynamics is assumed to be much shorter than the ion plasma and ion gyroperiods. Consequently, the ions do not respond to the wave potential and serve only as a neutralizing background. An equation determining the nonlinear evolution of the electrostatic potential in a plane perpendicular to an external magnetic field is derived within the drift approximation. The governing equation is then analyzed for the case with a localized shear in the electron fluid velocity. Possible final states of the diocotron instability are investigated analytically and solutions in the form of a tripolar vortex, a zonal flow, and a vortex street are found. The nonlinear time evolution of the diocotron instability is investigated by solving the governing equation numerically. In particular, the dynamics of nonlinearly saturated states and the formation of such states are discussed. Numerical solutions show a vortex street structure in a saturated state. The relevance of our investigation for space and laboratory plasmas is discussed.

show abstract

“…Recently, there has been a great deal of interest [1][2][3] in understanding the linear and nonlinear properties of finite amplitude low-frequency Alfvén-like waves in lowtemperature space and laboratory plasmas. The linear theory [4][5][6] focuses on the derivation of the dispersion relation and identifying the unstable wave spectra, whereas the nonlinear analyses [1][2][3][6][7][8] compute the saturation level of fluctuations as well as develop mode coupling equations which are needed for predicting the salient features of fully developed electromagnetic turbulence in nonuniform magnetized plasmas.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear dynamics of electromagnetic turbulence in a nonuniform magnetized plasma

1998

Self Cite

View full text Add to dashboard Cite

By using the hydrodynamic electron response with fixed ͑kinetic͒ ions along with Poisson's equation as well as Ampère's law, a system of nonlinear equations for low-frequency ͑in comparison with the electron gyrofrequency͒ long-͑short-͒ wavelength electromagnetic waves in a nonuniform resistive magnetoplasma has been derived. The plasma contains equilibrium density gradient and sheared equilibrium plasma flows. In the linear limit, local dispersion relations are obtained and analyzed. It is found that sheared equilibrium flows can cause instability of Alfvén-like electromagnetic waves even in the absence of a density gradient. Furthermore, it is shown that possible stationary solutions of the nonlinear equations without dissipation can be represented in the form of various types of vortices. On the other hand, the temporal behavior of our nonlinear dissipative systems without the equilibrium density inhomogeneity can be described by the generalized Lorenz equations which admit chaotic trajectories. The density inhomogeneity may lead to even qualitative changes in the chaotic dynamics. The results of our investigation should be useful in understanding the linear and nonlinear properties of nonthermal electromagnetic waves in space and laboratory plasmas.

show abstract

Formation of vortex chains in a nonuniform magnetized electron plasma

Abstract: It is shown that the equations governing the dynamics of weakly interacting medium-frequency electrostatic waves in a nonuniform magnetoplasma with a fixed ion background can have localized vortex chain solutions.

Cited by 5 publications

References 11 publications

Turbulence and transport in two-dimensional magnetized electron plasmas

Turbulence and transport in two-dimensional magnetized electron plasmas

Vortex formation in an electron plasma with a sheared flow

Nonlinear dynamics of electromagnetic turbulence in a nonuniform magnetized plasma

Contact Info

Product

Resources

About