The effect of waveguide boundary conditions on the spectrum resulting from the backscatter of lower hybrid waves near a waveguide array is calculated. It is found that the resulting k spectrum is peaked at multiples of 7r/b, where b is the waveguide width. This calculation may partially explain recent lower hybrid heating results on Alcator A.

Conditions for trapping of lower hybrid waves in plasma depletions in the Earth’s ionosphere are discussed. It is shown that the trapping can take place for the frequencies not only below but also above the lower hybrid resonance frequency of the background plasma, which is important for the formation of the downshifted maximum of the secondary electromagnetic emission. © 2007 Elsevier B.V. All...

COMSOL has been used to model the propagation of electromagnetic waves in fusion plasmas. For the first time, a finite element method has been used to solve the wave propagation for realistic fusion plasma parameters in the lower hybrid and ion cyclotron frequency ranges. Moreover, for lower hybrid waves, a new efficient iterative algorithm has been developed to take into account the dispersive...

Observed and theoretical features concerning the nature of so-called cometary "bow shocks" or "bow waves" are discussed. Collective plasma effects associated with the presence of pickup ring ions (protons and water ions) in the vicinity of the supermagnetosonic to submagnetosonic transition region in the quasi-perpendicular limit are considered; the linear and nonlinear evolution of instabiliti...