Publications in Scientific Journals:
F. Mink, M. Hoelzl, E. Wolfrum, F. Orain, M. Dunne, A. Lessig, S. Pamela, P. Manz, M. Maraschek, G. Huijsmans, M. Becoulet, F. Laggner, M. Cavedon, K. Lackner, S. Günter, U. Stroth, . ASDEX Upgrade Team:
"Nonlinear coupling induced toroidal structure of edge localized modes";
Edge localized modes (ELMs) are magnetohydrodynamic (MHD) instabilities that cause fast
periodic relaxations of the strong edge pressure gradient in tokamak fusion plasmas. A novel
diagnostic method allows the extraction of toroidal mode numbers, rotation velocities and
spatial information during the ELM cycle including the crash. While mode number branches
n = 3-6 and n = 8-10 are dominant just before the ELM crash, during the ELM crash
n = 2-5 are observed in typical discharges with type-I ELMs in the tokamak experiment.
These findings are compared to results from nonlinear MHD simulations. Although n = 6
is linearly dominant, nonlinear coupling in which n = 1 is particularly important leads to
the dominance of n = 3-5 during the ELM crash, in excellent agreement with experimental
observations. The simultaneous occurrence of these modes over a wide radial region leads to
high stochasticity and thus increased transport.
plasma, edge localized mode, nonlinear, mode number, JOREK
Created from the Publication Database of the Vienna University of Technology.