KINETIC ALFVEN EIGENMODES IN A HOT TOKAMAK PLASMA

Kinetic effects such as finite ion Larmor excursions and resonant Land au interactions are studied in the toroidicity Alfven eigenmode (TAE) range of frequencies. A new Alfven mode conversion mechanism is descri bed taking place away from the resonances through toroidal mode coupli ng. It generates a group of kinetic Alfven eigenmodes (KAE) in the nei ghbourhood of each fluid eigenmode, with wavefields that extend throug hout the plasma radius and could lead to substantial a particle losses . Comparisons carried out with measurements from the JET tokamak show that the multiple peaks observed on the response are KAE-induced in th e neighbourhood of an elongation-induced Alfven eigenmode.