Mitigation of electrostatic micro-instabilities by maximum-J effects in Chinese First Quasi-axisymmetric Stellarator (CFQS)
Abstract CFQS is the Chinese First Quasi-axisymmetric Stellarator which is characterized with very low neoclassical transport, good fast-ion confinement and ideal magnetohydrodynamic stability. In this work, we investigated systematically the suppression of electrostatic trapped electron modes (TEMs) via external controlling the maximum- J (second adiabatic invariant) condition in CFQS for the first time. It is found that the controllability of the maximum- J region can be realized by altering normalized plasma pressure β and adjusting the currents in poloidal field (PF) coils. The simulation results reveal that: (a) as β increases, the maximum- J region in the core expands, leading to a significant reduction in the growth rate of TEMs. Meanwhile, ion-temperature-gradient (ITG) modes do not show significant changes. (b) When the PF-coil current ( I PF ) is applied in the opposite direction to the magnetic field, the core maximum- J region also extends, resulting in considerable suppression of TEM instabilities, and the behavior of the ITG modes becomes slightly weak. This work provides insight into the mitigation of micro-instabilities in quasi-axisymmetric stellarators and provides two feasible methods to decrease micro-instabilities in future CFQS experiments.
Authors
- Jie Huang (ORCID: https://orcid.org/0000-0003-4179-943X)
- Yucai Li (ORCID: https://orcid.org/0000-0003-1630-014X)
- H. Lan (ORCID: https://orcid.org/0000-0001-8452-8635)
- A. Shimizu (ORCID: https://orcid.org/0000-0003-3764-3184)
- Haifeng Liu (ORCID: https://orcid.org/0000-0002-0424-645X)
- Xiaofeng Zheng
- Jun Hu (ORCID: https://orcid.org/0000-0002-4707-6550)
- J. Cheng (ORCID: https://orcid.org/0000-0002-0496-5542)
- M. Isobe (ORCID: https://orcid.org/0000-0002-3572-1882)
- P. Xanthopoulos (ORCID: https://orcid.org/0000-0003-3545-4822)
- T. Görler (ORCID: https://orcid.org/0000-0002-0851-6699)
- Hiromi Takahashi (ORCID: https://orcid.org/0000-0002-6041-1288)
- Wei Li (ORCID: https://orcid.org/0000-0003-0663-7638)
- Yuhong Xu (ORCID: https://orcid.org/0000-0003-4882-647X)
- Xianqu Wang (ORCID: https://orcid.org/0000-0001-8485-895X)
- Hai Liu (ORCID: https://orcid.org/0000-0001-6407-5958)
- Xiaofeng Zhang (ORCID: https://orcid.org/0000-0003-2738-3286)
- Junfeng Shen (ORCID: https://orcid.org/0000-0001-7273-0350)
- Changjian Tang
Institutions
- National Institutes of Natural Sciences (JP)
- The Graduate University for Advanced Studies, SOKENDAI (JP)
- National Institute for Fusion Science (JP)
- Max Planck Institute for Plasma Physics - Greifswald (DE)
- Max Planck Institute for Plasma Physics (DE)
- Southwest Jiaotong University (CN)
Publication Details
- Journal
- Plasma Physics and Controlled Fusion
- Published
- 2025-08-11
- DOI
- https://doi.org/10.1088/1361-6587/adfa3f
- Primary Topic
- Magnetic confinement fusion research
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China