Greifswald 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
P: Fachverband Plasmaphysik
P 12: Poster II
P 12.7: Poster
Tuesday, February 27, 2024, 16:30–18:30, ELP 6: Foyer
Characterization of electromagnetic instabilities in high-beta plasmas at Wendelstein 7-X — •Charlotte Büschel, Christian Brandt, Henning Thomsen, Kian Rahbarnia, Sara Vaz Mendes, Adrian von Stechow, and Jan-Peter Bähner — Max Planck Institute for Plasma Physics, Wendelsteinstr. 1, 17491 Greifswald, Germany
In the last campaigns of Wendelstein 7-X, comparable high plasma beta core values around β0 ∼ 2.5 % have been reached in different scenarios, e.g. after the injection of frozen hydrogen pellets or with heating scenarios combining electron cyclotron resonance heating and neutral beam injection. However maintaining the plasma in this state with plasma energies up to 1.2 MJ and densities around 1.4 × 1020 m−3 has up to date been challenging. With increasing density, strong mode activity in the range of 20-50 kHz has been observed, which might contribute to the decrease of the plasma energy and density after a transient peak. To determine the driving instability, these modes are characterized by analyzing data from Mirnov coils, the phase contrast imaging diagnostic and the soft X-ray tomography system. Furthermore the dependency on local and global plasma parameters is investigated.
Keywords: electromagnetic instabilities; high-beta plasmas; Wendelstein 7-X; Soft x-ray tomography; kinetic ballooning modes