Theory of plasma heating by low frequency waves: Magnetic pumping and Alfvén resonance heating

Abstract

The present status of the theory of plasma heating by low frequency waves is reviewed from a unified point of view based on the concept of the dielectric tensor operator.

Discrete spectrum of Alfvén ion–ion hybrid waves

“…2 and 3. The swept frequency data coincide with the dispersion relation associated with the lower Alfvén continuum edge and high-density core, and not the calculated discrete surface modes associated with the low-density edge ͑sometimes called surface quasielectrostatic modes 13,16 ͒.…”

“…15 The discrete Alfvén spectrum follows from many theoretical treatments of Alfvén waves, which include boundary conditions. 16,17 A cylindrical model, not a toroidal one, appears to be adequate to explain the data shown in this paper, even though the Phaedrus-T tokamak has significant toroidicity at an aspect ratio AϷ3. 7.…”

“…The Phaedrus-T experiments presented here along with the heating and current drive results have been carried out in a significantly different regime than the TCA experiments 13,16 that defined the genre of Alfvén heating experiments. Our wave frequency was near the cyclotron frequency / cH (r ϭ 0) Ϸ 0.7 Շ 1, and our toroidal mode numbers were large ͉n͉ӷ1.…”

“…If v Öz Ͻv e , theory predicts 16,20,21 mode conversion to a kinetic Alfvén wave ͑KAW͒, with substantial Landau damping onto the electrons.…”

“…In Fig. 11, we show ISMENE 16,30 calculations of the B (r) phase as a function of radius at the maximum computed antenna loading, for example, eigenmodes at nϭϪ5,Ϫ10, mϭϪ1. These two cases show mode conversion near the edge ͑nϭϪ5͒ and the core ͑nϭϪ10͒.…”