JET-P(95)30
Overview of Alfven Eigemode Experiments in JET
Results from the first experiments to drive Alfvén Eigenmodes (AE) with antennas external to a tokamak plasma are presented. In Ohmically heated plasma discharges, direct experimental measurements of the damping of Toroidicity induced AE (TAE) have allowed an identification of different regimes corresponding to different dominant TAE absorption mechanisms with a wide range of damping rates, 1o-3 ≤ γ/ω ≤ l0-1. In plasmas heated by ion cyclotron resonance heating, neutral beam injection heating, lower hybrid heating and high plasma current ohmic heating, a new class of weakly damped Alfvén eigenmodes. the Kinetic Alfvén Eigenmodes, predicted in theoretical models which include finite Larmor radius and finite parallel electric field effects, has been identified experimentally.