Publications in Scientific Journals:
G. Birkenmeier, M. Cavedon, G. Conway, P. Manz, U. Stroth, R. Fischer, G. Fuchert, T. Happel, F. Laggner, M. Maraschek, A. Medvedeva, V. Nikolaeva, D. Prisiazhniuk, T. Pütterich, F. Ryter, L. Shao, M. Willensdorfer, E. Wolfrum, H. Zohm, . ASDEX Upgrade Team:
"Magnetic structure and frequency scaling of limit-cycle oscillations close to L- to H-mode transitions";
Limit-cycle oscillations (LCOs) close to the power threshold of L- to H-mode transitions are
investigated in plasmas of ASDEX Upgrade. During this phase, referred to as I-phase, a strong
magnetic activity in the poloidal magnetic field B˙ with an up-down asymmetry is found. In
some cases, the regular LCOs during I-phase transition smoothly into a phase with intermittent
bursts which have similar properties to type-III edge localised modes (ELMs). Indications
of precursors during the intermittent phase as well as in the regular LCO phase point to a
common nature of the I-phase and type-III ELMs. The LCO frequency measured in a set of
discharges with different plasma currents and magnetic fields scales as f Bt I nT
3 2 ( / / )/( ).
magnetic confinement, pedestal, high confinement mode, L-H transition, limit-cycle oscillations, edge localized modes
Created from the Publication Database of the Vienna University of Technology.