Speaker
Description
Y. Narbutt1
, A. Mishchenko1
, A. Zocco1
, K. Aleynikova1
and R. Kleiber1
1 Max Planck Institute for Plasma Physics, Greifswald, 17489, Germany
Magnetic confinement fusion requires high 𝛽 = 〈𝑝〉/(𝐵
2/2𝜇0), the ratio of plasma pressure to
magnetic pressure, to access high performances. Moderate 𝛽 can be beneficial for iontemperature-gradient (ITG) driven turbulence. However, as 𝛽 is increased above a certain
threshold, the so-called kinetic-ballooning-mode (KBM) [1] can be destabilized. This is a
plasma pressure gradient driven instability, which is inherently electromagnetic and can lead to
strong outwards-directed heat fluxes [2], degrading plasma confinement in the process. While,
linearly, KBMs have been successfully studied in the stellarator Wendelstein 7-X with fluxtube simulations [3, 4], it was also shown that the instability tends to be most unstable while
developing a global structure on the magnetic surface. This poster presents results of global
linear simulations of KBMs in W7-X geometry using the global gyrokinetic code Euterpe [5].
This work has been carried out within the framework of the EUROfusion Consortium, funded by the
European Union via the Euratom Research and Training Programme (Grant Agreement No 101052200
— EUROfusion). Views and opinions expressed are however those of the author(s) only and do not
necessarily reflect those of the European Union or the European Commission. Neither the European
Union nor the European Commission can be held responsible for them.
References:
[1] W.M. Tang, J.W. Connor, and R.J. Hastie. “Kinetic-ballooning-mode theory in general geometry”.
In: Nuclear Fusion 20.11 (1980), p. 1439. doi: 10.1088/0029-5515/20/11/011.
[2] A. Mishchenko et al. “Gyrokinetic particle-in-cell simulations of electromagnetic turbulence in the
presence of fast particles and global modes”. In: Plasma Physics and Controlled Fusion 64.10 (2022),
p. 104009. doi: 10.1088/1361-6587/ac8dbc.
[3] K. Aleynikova, A. Zocco, and J. Geiger. “Influence of magnetic configuration properties on kinetic
ballooning modes in W7-X”. In: Journal of Plasma Physics 88.4 (2022), p. 905880411. doi:
10.1017/S0022377822000745.
[4] Ksenia Aleynikova and Alessandro Zocco. “Quantitative study of kinetic ballooning mode theory in
simple geometry”. In: Physics of Plasmas 24.9 (Aug. 2017). 092106. issn: 1070-664X. doi:
10.1063/1.5000052.
[5] R. Kleiber et. al. “EUTERPE: A global gyrokinetic code for stellarator geometry”. Submitted to
CPC. 2023
