Continuum modes in rotating plasmas: General equations and continuous spectra for large aspect ratio tokamaks

Lakhin, V. P.; Ilgisonis, V. I.

doi:10.1063/1.3628302

Cited by 25 publications

(17 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…22,23 The GAMs dispersion was studied in details in the framework of ideal MHD. [4][5][6][7] The hydrodynamical calculations agree with the kinetic approach. 8 The Landau damping could be taken into account as corrections to the oscillations dispersion.…”

Section: Introductionsupporting

confidence: 50%

“…A similar mode, the global acoustic mode (GAM), is well known in tokamak theory. [4][5][6][7][8] Both modes have similar frequency, but the angular mode number of pressure perturbations (m ¼ 0) in mirror traps is different from that of the GAM (m ¼ 1). However, if one identifies the toroidal wavenumber in a tokamak with azimuthal in a mirror trap, while the poloidal wavenumber with the axial one, respectively, than this difference vanishes.…”

Section: Introductionmentioning

confidence: 93%

See 1 more Smart Citation

Global sound modes in mirror traps with anisotropic pressure

2013

View full text Add to dashboard Cite

Global oscillations of inhomogeneous plasma with frequencies close to the bounce frequency of ions in mirror traps have been studied. It has been shown that, in some cases, the sound can be reflected from the axial plasma inhomogeneity. The ideal magnetohydrodynamic (MHD) model with ChewGoldberger-Low approximation has been utilized to determine conditions of existence of the standing waves in the mirror-confined plasma. Linearized wave equation for the longitudinal plasma oscillations in thin anisotropic inhomogeneous plasma with finite b has been derived. The wave equation has been treated numerically. The oscillations are studied for the case of the trap with partially filled loss-cone and the trap with sloshing ions. It has been shown that in cells of the multiple-mirror trap standing waves can exist. The frequency of the wave is of the order of the mean bounce-frequency of ions. In the trap with sloshing ions, the mode supported by the pressure of fast ions could exist. The results of oscillations observation in the experiment on the Gas Dynamic Trap have been presented. V C 2013 AIP Publishing LLC. [http://dx.

show abstract

Section: Introductionsupporting

confidence: 50%

Section: Introductionmentioning

confidence: 93%

Global sound modes in mirror traps with anisotropic pressure

2013

View full text Add to dashboard Cite

show abstract

“…Since n is small, we can iteratively solve (15). To the leading order, we drop the third term of (15) and obtain…”

Section: B Low Frequency Modesmentioning

confidence: 99%

“…The Alfenic continuum of a poloidally rotating plasma was investigated by Lakhin and Ilgisonis. 15 However, to study GAMs starting from fluid models, one can only obtain the real mode frequencies but obtain no information on mode damping or growth rates. Moreover, there are different closure choices that may lead to different results using fluid models.…”

Section: Introductionmentioning

confidence: 99%

Geodesic acoustic modes in tokamak plasmas with a radial equilibrium electric field

Zhou

2015

Physics of Plasmas

View full text Add to dashboard Cite

The dispersion relation of geodesic acoustic modes in the tokamak plasma with an equilibrium radial electric field is derived and analyzed. Multiple branches of eigenmodes have been found, similar to the result given by the fluid model with a poloidal mass flow. Frequencies and damping rates of both the geodesic acoustic mode and the sound wave increase with respect to the strength of radial electric field, while the frequency and the damping rate of the lower frequency branch slightly decrease. Possible connection to the experimental observation is discussed. V C 2015 AIP Publishing LLC. [http://dx.

show abstract

“…1 (henceforth referred to as I), it is a joy of recognition to re-encounter many of the results presented in the recent work by Lakhin and Ilgisonis, described in Ref. 2 (henceforth referred to as II). The aim of this comment is to indicate what is new in the analysis of II, compared to I, and to give some critical remarks on the assumptions and implications of the two papers.…”

mentioning

confidence: 99%

Comment on “Continuum modes in rotating plasmas: General equations and continuous spectra for large aspect ratio tokamaks” [Phys. Plasmas 18, 092103 (2011)]

Goedbloed

2012

Physics of Plasmas

View full text Add to dashboard Cite

It is shown that some of the main results of the recent paper by Lakhin and Ilgisonis [Phys. Plasmas 18, 092103 (2011)], viz. the derivation of the equations for the continuous spectra of poloidally and toroidally rotating plasmas and their special solution for large aspect ratio tokamaks with large parallel flows were obtained before by Goedbloed, Beliën, van der Holst, and Keppens [Phys. Plasmas 11, 28 (2004)]. A further rearrangement of the system of equations for the coupled Alfvén and slow continuous spectra clearly exhibits: (a) coupling through a single tangential derivative, which is a generalization of the geodesic curvature; (b) the “transonic” transitions of the equilibrium, which need to be carefully examined in order to avoid entering hyperbolic flow regimes where the stability formalism breaks down. A critical discussion is devoted to the implications of this failure, which is generally missed in the tokamak literature, possibly as a result of the wide-spread use of the sonic Mach number of gas dynamics, which is an irrelevant and misleading parameter in “transonic” magnetohydrodynamics. Once this obstacle in understanding is removed, further application of the theory of trans-slow Alfvén continuum instabilities to both tokamaks, with possible implications for the L-H transition, and astrophysical objects like “fat” accretion disks, with a possible new route to magnetohydrodynamic turbulence, becomes feasible.

show abstract

Continuum modes in rotating plasmas: General equations and continuous spectra for large aspect ratio tokamaks

Cited by 25 publications

References 36 publications

Global sound modes in mirror traps with anisotropic pressure

Global sound modes in mirror traps with anisotropic pressure

Geodesic acoustic modes in tokamak plasmas with a radial equilibrium electric field

Comment on “Continuum modes in rotating plasmas: General equations and continuous spectra for large aspect ratio tokamaks” [Phys. Plasmas 18, 092103 (2011)]

Contact Info

Product

Resources

About