Mode conversion and dissipation of the fast Alfvén wave in ion cyclotron heating

1989 ◽  
Vol 1 (2) ◽  
pp. 350-357 ◽  
Author(s):  
R. A. Cairns ◽  
V. Fuchs
Keyword(s):  
Mode Conversion ◽  
Alfven Wave ◽  
Ion Cyclotron

scholarly journals Collisionless Damping of Fast and Ion?Cyclotron Surface Waves

1993 ◽  
Vol 46 (2) ◽  
pp. 271 ◽  
Author(s):  
GW Rowe
Keyword(s):  
Surface Waves ◽  
Short Wavelength ◽  
Mode Conversion ◽  
Low Frequency ◽  
Wave Mode ◽  
Alfven Wave ◽  
Field Boundary ◽  
First Order ◽  
Vacuum Interface ◽  
Ion Cyclotron

A recently developed general kinetic theory of surface waves is used to calculate the collisionless damping of low frequency fast and ion-cyclotron surface waves on a magnetised plasma-vacuum interface. In particular, the possibility of Cherenkov (Landau and transit-time magnetic) absorption by electrons is accounted for, assuming a bi-Maxwellian distribution of electrons in velocity space. It is shown that in general the surface waves are damped via mode conversion to a short-wavelength mode, such as the kinetic Alfven wave, which is subsequently Landau absorbed within the plasma. For high temperatures this short-wavelength mode can also be radiated into the plasma without being completely absorbed. It is also shown that the related ion-sound surface wave mode and instability identified by Alexandrov et al. (1984) are unphysical, and are the result of neglecting the gas pressure in the first-order magnetic field boundary condition.

Ion cyclotron range of frequency mode conversion flow drive in D(3He) plasmas on JET

2012 ◽  
Vol 54 (7) ◽  
pp. 074001 ◽  
Author(s):  
Y Lin ◽  
P Mantica ◽  
T Hellsten ◽  
V Kiptily ◽  
E Lerche ◽  
...  
Keyword(s):  
Mode Conversion ◽  
Frequency Mode ◽  
Ion Cyclotron

scholarly journals Alfvén resonance absorption in electron-positron plasmas

2010 ◽  
Vol 6 (S274) ◽  
pp. 224-227 ◽  
Author(s):  
N. F. Cramer
Keyword(s):  
Mode Conversion ◽  
Alfven Wave ◽  
Pulsar Magnetosphere ◽  
Pulsar Radio ◽  
Inertial Alfvén Wave ◽  
Pair Plasma ◽  
Electron Positron ◽  
Normal Electron ◽  
The Magnetic Field ◽  
Pulsar Radio Emission

AbstractWaves propagating obliquely in a magnetized cold pair plasma experience an approximate resonance in the wavevector component perpendicular to the magnetic field, which is the analogue of the Alfvén resonance in normal electron-ion plasmas. Wave absorption at the resonance can take place via mode conversion to the analogue of the short wavelength inertial Alfvén wave. The Alfvén resonance could play a role in wave propagation in the pulsar magnetosphere leading to pulsar radio emission. Ducting of waves in strong plasma gradients may occur in the pulsar magnetosphere, which leads to the consideration of Alfvén surface waves, whose energy is concentrated in the region of strong gradients.

Mode conversion and electron damping of the fast Alfvén wave in a tokamak at the ion–ion hybrid frequency

1995 ◽  
Vol 2 (5) ◽  
pp. 1637-1647 ◽  
Author(s):  
V. Fuchs ◽  
A. K. Ram ◽  
S. D. Schultz ◽  
A. Bers ◽  
C. N. Lashmore‐Davies
Keyword(s):  
Mode Conversion ◽  
Alfven Wave ◽  
Hybrid Frequency

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.

scholarly journals Evolution of Alfvén wave-driven solar winds to red giants

2007 ◽  
Vol 3 (S247) ◽  
pp. 201-207
Author(s):  
Takeru K. Suzuki
Keyword(s):  
Solar Wind ◽  
Mode Conversion ◽  
Alfven Waves ◽  
Alfven Wave ◽  
Alfvén Waves ◽  
Stellar Winds ◽  
Red Giants ◽  
Giant Stars ◽  
Solar Winds ◽  
Red Giant

AbstractIn this talk we introduce our recent results of global 1D MHD simulations for the acceleration of solar and stellar winds. We impose transverse photospheric motions corresponding to the granulations, which generate outgoing Alfvén waves. The Alfvén waves effectively dissipate by 3-wave coupling and direct mode conversion to compressive waves in density-stratified atmosphere. We show that the coronal heating and the solar wind acceleration in the open magnetic field regions are natural consequence of the footpoint fluctuations of the magnetic fields at the surface (photosphere). We also discuss winds from red giant stars driven by Alfvén waves, focusing on different aspects from the solar wind. We show that red giants wind are highly structured with intermittent magnetized hot bubbles embedded in cool chromospheric material.

scholarly journals Reflection at the resonance layer of the fast Alfvén wave in ion cyclotron heating

1990 ◽  
Vol 2 (9) ◽  
pp. 2185-2190 ◽  
Author(s):  
C. Chow ◽  
V. Fuchs ◽  
A. Bers
Keyword(s):  
Alfven Wave ◽  
Ion Cyclotron

Observation of Ion-Cyclotron-Frequency Mode-Conversion Flow Drive in Tokamak Plasmas

2008 ◽  
Vol 101 (23) ◽  
Author(s):  
Y. Lin ◽  
J. E. Rice ◽  
S. J. Wukitch ◽  
M. J. Greenwald ◽  
A. E. Hubbard ◽  
...  
Keyword(s):  
Cyclotron Frequency ◽  
Mode Conversion ◽  
Frequency Mode ◽  
Tokamak Plasmas ◽  
Ion Cyclotron
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