Tomographic investigation into global Alfvén eigenmodes at the stellarator Wendelstein 7-AS
The magnetohydrodynamic (MHD) activity of plasma is of relevance in fusion experiments. By reconstructing the local X-emissivity tomographically, the activity can be analysed. The technical discussion of this thesis deals with the construction and the use of the tomographic system, while the physical results refer to MHD activity. The tomographic system allows readings which are precise enough to be compared to calculated configurations. Good agreement was reached, thus an important verification of the numerical calculations can be achieved. The MHD activity shows periodical, global and coherent structures called modes. Calculations predict the existence of global Alfvén eigenmodes (GAE) in the gaps of the Alfvén continua. By using the X-tomographic systems, possible mode numbers and characteristic functions can be measured for the first time.
Bibliographic Reference: Report: IPP III/230 DE (1998) 177pp.
Availability: Available from the Max-Planck-Institut für Plasmaphysik, 85748 Garching bei München (DE)
Record Number: 199810658 / Last updated on: 1998-06-08
Original language: de
Available languages: de