Numerical study of the synergy effects of electron cyclotron wave and two lower-hybrid waves in the current drive process

Nonlinear excitation of electrostatic and magnetostatic zero-frequency modes by finite-amplitude lower-hybrid waves is considered. It is found that modulational instabilities can give rise to enhanced plasma vortices. Dispersion relations, as well as analytical expressions for the growth rates, are obtained. The enhanced vortices may cause anomalous cross-field diffusion which can affect plasma confinement in tokamak devices when lower-hybrid waves are used for plasma heating or current drive. We found that magnetic fluctuations associated with the parametrically driven magnetostatic mode are of particular importance in tokamak plasmas.

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Simulation of propagation, absorption and current drive efficiency of lower hybrid waves in reactor relevant JET discharges

10.1063/1.38535 ◽

1989 ◽

Author(s):

M. Brusati ◽

C. Gormezano ◽

S. Knowlton ◽

M. Lorentz-Gottardi( ◽

F. Rimini

Keyword(s):

Current Drive ◽

Lower Hybrid ◽

Hybrid Waves ◽

Lower Hybrid Waves

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Lower-hybrid instability in current-carrying plasmas

Journal of Plasma Physics ◽

10.1017/s0022377800000465 ◽

1982 ◽

Vol 28 (3) ◽

pp. 527-537 ◽

Cited By ~ 1

Author(s):

Joseph E. Willett ◽

Hassan Mehdian

Keyword(s):

Phase Velocity ◽

Drift Velocity ◽

Numerical Study ◽

Electron Drift Velocity ◽

Lower Hybrid ◽

Electron Drift ◽

Plasma Parameters ◽

The Stability ◽

Hybrid Waves ◽

Lower Hybrid Waves

The stability of lower-hybrid waves in a collisional, fully ionized plasma carrying a field-aligned current is investigated. From the two-fluid equations in the cold-plasma approximation, a generalized dispersion relation and formulae for the real frequency ωI and growth rate ωR are derived. The results of a numerical study are presented showing the dependence of ωR and ωI on the angle between the direction of propagation and the magnetic field, the ratio of the electron drift velocity to the parallel phase velocity, and other plasma parameters. Lower-hybrid instability with electron drift velocity small compared with the parallel phase velocity is predicted.

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Central current profile control by electron cyclotron waves and lower hybrid waves in tokamak plasmas

Nuclear Fusion ◽

10.1088/0029-5515/29/8/014 ◽

1989 ◽

Vol 29 (8) ◽

pp. 1381-1384 ◽

Cited By ~ 4

Author(s):

G. Giruzzi ◽

I. Fidone ◽

R.L. Meyer

Keyword(s):

Electron Cyclotron ◽

Lower Hybrid ◽

Tokamak Plasmas ◽

Current Profile ◽

Profile Control ◽

Electron Cyclotron Waves ◽

Hybrid Waves ◽

Lower Hybrid Waves

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On the dependence of the efficiency of lower-hybrid current drive on the wave spectrum

Journal of Plasma Physics ◽

10.1017/s002237780001415x ◽

1989 ◽

Vol 42 (1) ◽

pp. 1-12

Author(s):

Aldo Nocentini

Keyword(s):

Electric Field ◽

Simple Formula ◽

Wave Spectrum ◽

Current Drive ◽

Lower Hybrid ◽

One Dimensional ◽

Lower Hybrid Current Drive ◽

Hybrid Waves ◽

Lower Hybrid Waves ◽

Kinetic Treatment

The dependence of the efficiency of current drive by lower-hybrid waves on the shape and intensity of the wave spectrum is discussed in the case where no d.c. electric field is present. The discussion is based on a simple formula arising from a one-dimensional kinetic treatment of the problem.

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