Greifswald 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
P: Fachverband Plasmaphysik
P 25: Poster III
P 25.8: Poster
Thursday, February 29, 2024, 16:30–18:30, ELP 6: Foyer
Overview of mode observations at the Wendelstein 7-X stellarator — •Kian Rahbarnia1, Ksenia Aleynikova1, Tamara Andreeva1, Jan-Peter Bähner2, Charlotte Büschel1, Christian Brandt1, Neha Chaudhary1, Dario Cipciar1, Mykola Dreval3, Carsten Killer1, Ralf Kleiber1, Axel Könies1, Andreas Krämer-Flecken4, Sara Vaz Mendes1, Christoph Slaby1, Adrian von Stechow1, Henning Thomsen1, Gavin Weir1, and Wendelstein 7-X1 — 1Max Planck Institute for Plasma Physics, Greifswald, Germany — 2MIT Plasma Science and Fusion Center, Cambridge, MA, USA — 3Kharkov Institute of Physics and Technology, Kharkov, Ukraine — 4Forschungszentrum Jülich GmbH, Jülich, Germany
During the recent operational phase OP2.1 at the optimized stellarator Wendelstein 7-X in Greifswald, Germany, a large variety of mode activity in a broad frequency range from about 1-1000 kHz has been observed. This work provides an overview of measurements, which are partly accompanied by theoretical calculations. The focus lays on Alfvénic activity around 200 kHz and potentially fast ion driven modes in plasmas heated by neutral beam injection or ion cyclotron resonance heating. Additionally observations of trapped electron modes are discussed. Mode activity around 10-50 kHz, which is specifically observed in higher beta plasmas, is related to theoretically predicted kinetic ballooning modes and finally low frequency island localized modes around 1 kHz are investigated. Both last aspects might have impact on confinement properties in future highest beta plasmas.
Keywords: Alfvén waves; electromagnetic modes; magnetohydrodynamik; magnetic confinement; stellarator