Cross-Field Ion Transport and Heating Due to Parametric Decay of Lower Hybrid Waves

Characterization of onset of parametric decay instability of lower hybrid waves

The goal of the lower hybrid current drive (LHCD) program on Alcator C-Mod is to develop and optimize ITERrelevant steady-state plasmas by controlling the current density profile. Using a 4x16 waveguide array, over 1 MW of LH power at 4.6 GHz has been successfully coupled to the plasmas. However, current drive efficiency precipitously drops as the line averaged density (ne) increases above 1020...

Resonant Parametric Excitation in Lower-hybrid Heating of Tokamak Plasma*

Stochastic Ion Heating by a Lower Hybrid Wave: II

∣ ≪ |k⊥| and ω ≫ Ωi) in a tokamak plasma is studied. For ions satisfying v⊥ > ω/k⊥, the Lorentz force law for the ions is reduced to a set of difference equations which give the Larmor radius and phase of an ion on one cyclotron orbit in terms of these quantities a cyclotron period earlier. From these difference equations an earlier result [Phys. Fluids 21, 1584 (1978)] that above a certain wav...

Electromagnetic particle simulation of the linear mode conversion and the nonlinear parametric decay instability of lower hybrid waves in tokamaks

In plasma simulations where the speed of light times a characteristic length is at a much higher frequency than the relevant parameters in the system, such as the plasma frequency, implicit methods begin to play an important role in generating e cient solutions in these multi-scale problems. Under conditions of scale separation, one can rescale Maxwell’s equations in such a way as to give a mag...

Pfc / Ja - 83 - 9 Parametric Excitation of Ion - Sound Quasi - Modes during Lower Hybrid Heating Experiments in Tokamaks

and disposal, in whole or in part by or for the United States government is permitted. By acceptance of this article, the publisher and/or recipient acknowledges the U.S. Government's right to retain a non-exclusive, royalty-free license in and to any copyright covering this paper. Parametric decay of a lower hybrid pump wave into another lower hybrid wave and a low frequency ion-sound quasi-mo...