Finite Larmor radius wave equations in Tokamak plasmas in the ion cyclotron frequency range

1989 ◽  
Vol 31 (5) ◽  
pp. 723-757 ◽  
Author(s):  
M Brambilla
Keyword(s):  
Wave Equations ◽  
Cyclotron Frequency ◽  
Larmor Radius ◽  
Tokamak Plasmas ◽  
Frequency Range ◽  
Finite Larmor Radius ◽  
Ion Cyclotron

On the modelling of fundamental ion cyclotron absorption by finite Larmor radius wave equations

1994 ◽  
Vol 50 (3) ◽  
pp. 275-282 ◽  
Author(s):  
M J Alava ◽  
J A Heikkinen ◽  
T Hellsten ◽  
I Pavlov ◽  
O N Shcherbinin
Keyword(s):  
Wave Equations ◽  
Larmor Radius ◽  
Finite Larmor Radius ◽  
Cyclotron Absorption ◽  
Ion Cyclotron

scholarly journals Novel internal measurements of ion cyclotron frequency range fast-ion driven modes

2021 ◽  
Author(s):  
Neal A Crocker ◽  
Shawn X Tang ◽  
Kathreen E Thome ◽  
Jeff Lestz ◽  
Elena Belova ◽  
...  
Keyword(s):  
Cyclotron Frequency ◽  
Harmonic Wave ◽  
Wave Number ◽  
Frequency Range ◽  
High Wave Number ◽  
Minor Radius ◽  
Ion Cyclotron ◽  
Cyclotron Emission ◽  
Edge Localized Modes ◽  
Fast Ion

Abstract Novel internal measurements and analysis of ion cyclotron frequency range fast-ion driven modes in DIII-D are presented. Observations, including internal density fluctuation (ñ) measurements obtained via Doppler Backscattering, are presented for modes at low harmonics of the ion cyclotron frequency localized in the edge. The measurements indicate that these waves, identified as coherent Ion Cyclotron Emission (ICE), have high wave number, _⊥ρ_fast ≳ 1, consistent with the cyclotron harmonic wave branch of the magnetoacoustic cyclotron instability (MCI), or electrostatic instability mechanisms. Measurements show extended spatial structure (at least ~ 1/6 the minor radius). These edge ICE modes undergo amplitude modulation correlated with edge localized modes (ELM) that is qualitatively consistent with expectations for ELM-induced fast-ion transport.

scholarly journals Comments on finite Larmor radius models for ion cyclotron range of frequencies heating in tokamaks

1994 ◽  
Vol 1 (12) ◽  
pp. 3905-3907 ◽  
Author(s):  
C. K. Phillips ◽  
J. R. Wilson ◽  
J. C. Hosea ◽  
R. Majeski ◽  
D. N. Smithe
Keyword(s):  
Larmor Radius ◽  
Finite Larmor Radius ◽  
Ion Cyclotron

Alfvén wave heating of a cylindrical plasma using axisymmetric waves. Part 2. Kinetic theory

1986 ◽  
Vol 35 (1) ◽  
pp. 75-106 ◽  
Author(s):  
I. J. Donnelly ◽  
B. E. Clancy ◽  
N. F. Cramer
Keyword(s):  
Kinetic Theory ◽  
Wave Equations ◽  
Compressional Wave ◽  
Alfven Wave ◽  
Larmor Radius ◽  
Electrostatic Wave ◽  
Hot Plasma ◽  
Wave Heating ◽  
Ion Cyclotron ◽  
Consequent Increase

Kinetic theory, including ion Larmor radius effects, is used to analyse the Alfvén wave heating of cylindrical plasmas using axisymmetric waves excited by an antenna at frequencies up to the ion cyclotron frequency. At the Alfvén resonance position, the compressional wave is mode converted to a quasi-electrostatic wave (QEW) which propagates towards the plasma centre or edge depending on whether the plasma is hot or warm. The energy absorbed by the plasma agrees with the MHD theory predictions provided the QEW is heavily damped before reaching the plasma centre or edge; if it is not, then QEW resonances may occur with a consequent increase in antenna resistance. The relation between ion cyclotron wave resonances and QEW resonances in a hot plasma is shown. The behaviour described above is demonstrated by numerical solution of the wave equations for small and large tokamak-like plasmas. WKB theory has been used to derive useful expressions which quantify the QEW behaviour.

Ion- and electron-acoustic waves in sheet plasmas

1989 ◽  
Vol 41 (2) ◽  
pp. 281-287
Author(s):  
M. B. Chaudhry ◽  
M. D. Tahir
Keyword(s):  
Acoustic Waves ◽  
Cyclotron Frequency ◽  
Larmor Radius ◽  
Frequency Range ◽  
Ion Temperature ◽  
Temperature Ratio ◽  
Ion Acoustic Waves ◽  
Poisson Equations ◽  
Electron Acoustic Waves ◽  
Electron Acoustic

Ion-acoustic waves in sheet plasmas, which are of thickness of order of the ion Larmor radius ρi, have been investigated numerically. The frequency range considered is less than the ion cyclotron frequency ωci. An integral equation in wavenumber space is derived from the linearized Vlasov-Poisson equations and analysed numerically. Eigenfrequencies and eigenfunctions of the wave have been studied systematically by varying the plasma thickness, plasma density, electron-to-ion temperature ratio and parallel wavenumber. Electron-acoustic waves are found when the parallel wavenumber is very small (e.g. k∥ρi = 0·005) and the electron and ion temperatures are comparable.

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