Toroidal mode-conversion in the ICRF
Several toroidal kinetic codes have been developed for global wave calculations in the ion-cyclotron range of frequencies, taking into account the geometry, the gyro-orbit width of the particles, the Landau damping and the parallel electric field to various degrees of refinement, producing results which were sometimes in good agreement with experimental measurements. A convincing toroidal calculation showing how the fast wave converts to a slow wave, which propagates and deposits energy through resonant wave-particle interactions has however not been given so far, even if this is required to determine only which species finally absorbs the power. In this paper, the gyrokinetic toroidal PENN code is used to answer this question, comparing toroidal mode-conversion calculations with the simplified predictions from the gyrokinetic slab ISMENE and the fluid toroidal LION codes. After a reminder of the principles behind the physical phenomenon, all three models used in the paper are briefly described with their possibilities and limitations. A DIII-D equilibrium is then analysed for a mode-conversion scenario, showing that toroidal and kinetic effects are both important, and that toroidicity can strongly increase the efficiency of the mode conversion.
Bibliographic Reference: Article: Nuclear Fusion (1997)
Record Number: 199711279 / Last updated on: 1997-10-10
Original language: en
Available languages: en