Electromagnetic effects on geodesic acoustic modes

Smolyakov, A. I.; Elfimov, A. G.; Melnikov, A. V.; Murtaza, G.

doi:10.1063/1.4891883

Title: Electromagnetic effects on geodesic acoustic modes

Full Record
Other Related Research

Abstract

By using the full electromagnetic drift kinetic equations for electrons and ions, the general dispersion relation for geodesic acoustic modes (GAMs) is derived incorporating the electromagnetic effects. It is shown that m = 1 harmonic of the GAM mode has a finite electromagnetic component. The electromagnetic corrections appear for finite values of the radial wave numbers and modify the GAM frequency. The effects of plasma pressure β{sub e}, the safety factor q, and the temperature ratio τ on GAM dispersion are analyzed.

Authors:

Smolyakov, A. I. ^[1]; Elfimov, A. G. ^[2]; Melnikov, A. V. ^[3]; Murtaza, G. ^[4]

University of Saskatchewan, 116 Science Place, Saskatoon S7N 5E2 (Canada)
Institute of Physics, University of São Paulo, São Paulo 05508-090 (Brazil)
Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow (Russian Federation)
Visiting Professor, Department of Physics, Quaid-e-Azam University, Islamabad (Pakistan)

Publication Date:: Fri Aug 15 00:00:00 EDT 2014

OSTI Identifier:: 22303776

Resource Type:: Journal Article

Journal Name:: Physics of Plasmas

Additional Journal Information:: Journal Volume: 21; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CORRECTIONS; DISPERSION RELATIONS; DISPERSIONS; ELECTRONS; KINETIC EQUATIONS; PLASMA PRESSURE; SAFETY

Citation Formats


                    Bashir, M. F., E-mail: frazbashir@yahoo.com, Department of Physics, G. C. University Lahore, Katchery Road, Lahore 54000, Smolyakov, A. I., Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow, Elfimov, A. G., Melnikov, A. V., National Research Nuclear University MEPhI, 115409, Moscow, and Murtaza, G. Electromagnetic effects on geodesic acoustic modes.  United States: N. p., 2014. 
        Web.  doi:10.1063/1.4891883.

Copy to clipboard


                    Bashir, M. F., E-mail: frazbashir@yahoo.com, Department of Physics, G. C. University Lahore, Katchery Road, Lahore 54000, Smolyakov, A. I., Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow, Elfimov, A. G., Melnikov, A. V., National Research Nuclear University MEPhI, 115409, Moscow, & Murtaza, G. Electromagnetic effects on geodesic acoustic modes.  United States.  https://doi.org/10.1063/1.4891883

Copy to clipboard


                    Bashir, M. F., E-mail: frazbashir@yahoo.com, Department of Physics, G. C. University Lahore, Katchery Road, Lahore 54000, Smolyakov, A. I., Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow, Elfimov, A. G., Melnikov, A. V., National Research Nuclear University MEPhI, 115409, Moscow, and Murtaza, G. 2014.  
        "Electromagnetic effects on geodesic acoustic modes".  United States.  https://doi.org/10.1063/1.4891883.

Copy to clipboard


                    
@article{osti_22303776,

  title        = {Electromagnetic effects on geodesic acoustic modes},

  author       = {Bashir, M. F., E-mail: frazbashir@yahoo.com and Department of Physics, G. C. University Lahore, Katchery Road, Lahore 54000 and Smolyakov, A. I. and Institute of Tokamak Physics, NRC “Kurchatov Institute,” 123182 Moscow and Elfimov, A. G. and Melnikov, A. V. and National Research Nuclear University MEPhI, 115409, Moscow and Murtaza, G.},

  abstractNote = {By using the full electromagnetic drift kinetic equations for electrons and ions, the general dispersion relation for geodesic acoustic modes (GAMs) is derived incorporating the electromagnetic effects. It is shown that m = 1 harmonic of the GAM mode has a finite electromagnetic component. The electromagnetic corrections appear for finite values of the radial wave numbers and modify the GAM frequency. The effects of plasma pressure β{sub e}, the safety factor q, and the temperature ratio τ on GAM dispersion are analyzed.},

  doi          = {10.1063/1.4891883},

  url          = {https://www.osti.gov/biblio/22303776},
  journal      = {Physics of Plasmas},

  issn         = {1070-664X},

  number       = 8,

  volume       = 21,

  place        = {United States},

  year         = {Fri Aug 15 00:00:00 EDT 2014},

  month        = {Fri Aug 15 00:00:00 EDT 2014}

}

Copy to clipboard

Journal Article:

https://doi.org/10.1063/1.4891883

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

Energetic-particle-induced electromagnetic geodesic acoustic mode in tokamak plasmas

Journal Article Wang, Lingfeng; He, Zhixiong; He, Hongda; ... - Physics of Plasmas

Energetic-particle-induced kinetic electromagnetic geodesic acoustic modes (EKEGAMs) are numerically studied in low β (=plasma pressure/magnetic pressure) tokamak plasmas. The parallel component of the perturbed vector potential is considered along with the electrostatic potential perturbation. The effects of finite Larmor radius and finite orbit width of the bulk and energetic ions as well as electron parallel dynamics are all taken into account in the dispersion relation. Systematic harmonic and ordering analysis are performed for frequency and growth rate spectra of the EKEGAMs, assuming (kρ{sub i})∼q{sup −3}∼β≪1, where q, k, and ρ{sub i} are the safety factor, radial component of the EKEGAMsmore »« less
https://doi.org/10.1063/1.4890467
Electromagnetic effects of kinetic geodesic acoustic mode in tokamak plasmas

Journal Article Lingfeng, Wang; Shen, Y; He, H; ... - Physics of Plasmas

Electromagnetic effects of the kinetic geodesic acoustic modes (KGAMs) are numerically studied in low {beta}(= plasma pressure/magnetic pressure) tokamak plasmas. The parallel component of the perturbed vector potential is considered along with the electrostatic potential perturbation. The finite Larmor radius and finite orbit width of the ions as well as electron parallel dynamics are all taken into account. Systematic harmonic and ordering analysis is performed for collisionless damping of the KGAMs, assuming {beta}{approx}({kappa}{rho}{sub i}){sup 2}, where {kappa}and {rho}{sub i}are the radial component of the KGAM wave vector and the Larmor radius of the ions, respectively. It is found that themore »« less
https://doi.org/10.1063/1.3590892
Fully Nonlinear Edge Gyrokinetic Simulations of Kinetic Geodesic-Acoustic Modes and Boundary Flows

Conference Xu, X; Belli, E; Bodi, K; ...

We present edge gyrokinetic neoclassical simulations of tokamak plasmas using the fully nonlinear (full-f) continuum code TEMPEST. A nonlinear Boltzmann model is used for the electrons. The electric field is obtained by solving the 2D gyrokinetic Poisson Equation. We demonstrate the following: (1) High harmonic resonances (n > 2) significantly enhance geodesic-acoustic mode (GAM) damping at high-q (tokamak safety factor), and are necessary to explain both the damping observed in our TEMPEST q-scans and experimental measurements of the scaling of the GAM amplitude with edge q{sub 95} in the absence of obvious evidence that there is a strong q dependencemore »« less
Full Text Available
Drift effects on electromagnetic geodesic acoustic modes

Journal Article Sgalla, R. - Physics of Plasmas

A two fluid model with parallel viscosity is employed to derive the dispersion relation for electromagnetic geodesic acoustic modes (GAMs) in the presence of drift (diamagnetic) effects. Concerning the influence of the electron dynamics on the high frequency GAM, it is shown that the frequency of the electromagnetic GAM is independent of the equilibrium parallel current but, in contrast with purely electrostatic GAMs, significantly depends on the electron temperature gradient. The electromagnetic GAM may explain the discrepancy between the f ∼ 40 kHz oscillation observed in tokamak TCABR [Yu. K. Kuznetsov et al., Nucl. Fusion 52, 063044 (2012)] and the former prediction formore »« less
https://doi.org/10.1063/1.4907196
Excitation of kinetic geodesic acoustic modes by drift waves in nonuniform plasmas

Journal Article Qiu, Z.; Chen, L.; Zonca, F. - Physics of Plasmas

Effects of system nonuniformities and kinetic dispersiveness on the spontaneous excitation of Geodesic Acoustic Mode (GAM) by Drift Wave (DW) turbulence are investigated based on nonlinear gyrokinetic theory. The coupled nonlinear equations describing parametric decay of DW into GAM and DW lower sideband are derived and then solved both analytically and numerically to investigate the effects on the parametric decay process due to system nonuniformities, such as nonuniform diamagnetic frequency, finite radial envelope of DW pump, and kinetic dispersiveness. It is found that the parametric decay process is a convective instability for typical tokamak parameters when finite group velocities ofmore »« less
https://doi.org/10.1063/1.4863973

Similar Records