Observation of toroidicity-induced Alfvén eigenmodes in ohmically heated plasmas by drift wave excitation
At ASDEX Upgrade, in ohmically heated discharges magnetohydrodynamic (MHD) modes have been observed, scaling with frequencies pointing towards Alfvénic-type modes. Considering a local approximation for the frequency of toroidicity-induced Alfvén eigenmodes (TAE-modes), a value for the localization of the modes of q = 2.6 results. More detailed calculations predict TAE-modes with the corresponding frequencies at this location. The excitation of TAE-modes without fast particles can be explained by the coupling of the electromagnetic part of the drift Alfvén turbulence at the plasma edge to the ordinary Alfvén wave spectrum.
Bibliographic Reference: Article: Physical Review Letters, Vol. 79 (1997) No. 21, pp. 4186-4189
Record Number: 199810521 / Last updated on: 1998-05-05
Original language: en
Available languages: en