Investigation of tearing modes in asymmetric elongated plasmas in the ASDEX Upgrade tokamak
One of the most important research topics in the broad range of fusion experiments is that of disruptions, and more particularly the modulations of the poloidal magnetic field that occur before disruptions. The main aim of this project was to determine the structure of perturbative fields prior to disruptions in the reactor-speckle geometry of the tokamak experiment ASDEX Upgrade. It was also necessary to provide a means of identifying possible perturbative current distributions from equilibrium analysis of ASDEX Upgrade and to calculate the resulting fields outside the plasma. The calculated fields were compared to the measurements in order to verify assumptions concerning perturbative current distribution. In order to create a broad data base, signals from a large number of measuring coils had to be stored in high temporal resolution. From perturbative fields calculated and verified from the measurements, the shape and size of the disruption and its effect on plasma equilibrium were determined. This newly developed method of analysis is particularly suited to the investigation of density limit disruptions.
Bibliographic Reference: Report: IPP 1/289 DE (1995) 101 pp.
Availability: Available from Max-Planck-Institut für Plasmaphysik, 8046 Garching bei München (DE)
Record Number: 199511202 / Last updated on: 1995-10-10
Original language: de
Available languages: de