Active tungsten expulsion in ELM-absent H-mode plasmas via on-demand ELM triggering with lithium granule injection
Abstract Lithium granules gravitationally injected into the upper X -point region demonstrated on-demand edge-localized modes (ELM) triggering in otherwise ELM-suppressed H-mode plasmas on the Experimental Advanced Superconducting Tokamak. Sub-mm lithium granules dropped into enhanced D-alpha H-mode plasmas achieved a high triggering efficiency, while enabling ELM frequencies from several to hundreds of hertz. Core radiation from heavy impurities, dominated by W, was reduced by up to 60%, and the normalized energy confinement increased by up to 30%. At low injection frequencies, ELMs of substantially reduced size compared to spontaneous type-I ELMs were observed. At high injection frequencies, a transition to a mixed ELM phase occurred, characterized by intermittent larger ELMs and suppression of the quasi-coherent mode, achieving the most significant W reduction and energy confinement improvement. These results highlight a promising pathway for active W control via controlled, small ELMs in long-pulse, high-performance scenarios.
Authors
- R. Lunsford (ORCID: https://orcid.org/0000-0003-3588-6801)
- Yunxin Cheng (ORCID: https://orcid.org/0000-0002-9195-2757)
- A. Nagy (ORCID: https://orcid.org/0000-0002-8201-2528)
- Jiansheng Hu (ORCID: https://orcid.org/0000-0002-8252-0960)
- A. Diallo (ORCID: https://orcid.org/0000-0002-0706-060X)
- Xiaojing Gong (ORCID: https://orcid.org/0000-0002-8221-3522)
- Wei Wang (ORCID: https://orcid.org/0009-0007-6479-6326)
- R. Maingi (ORCID: https://orcid.org/0000-0003-1238-8121)
- Huiqian Wang (ORCID: https://orcid.org/0000-0003-1920-2799)
- Kexin Jia (ORCID: https://orcid.org/0009-0000-0558-0006)
- Zhe Wang (ORCID: https://orcid.org/0009-0007-6857-1431)
- De-Min Wu (ORCID: https://orcid.org/0000-0002-2457-1049)
- J. Huang (ORCID: https://orcid.org/0000-0001-5662-809X)
- Hailin Zhao (ORCID: https://orcid.org/0000-0002-6298-1217)
- K. Tritz
- A. Bortolon (ORCID: https://orcid.org/0000-0002-0094-0209)
- Guizhong Zuo (ORCID: https://orcid.org/0000-0002-4149-089X)
- Yifeng Wang (ORCID: https://orcid.org/0000-0002-0368-9566)
- Qing Hua Zhang (ORCID: https://orcid.org/0000-0002-6595-8995)
- Tao Zhang (ORCID: https://orcid.org/0000-0002-1555-6226)
- Ling Zhang (ORCID: https://orcid.org/0000-0001-6480-6917)
- Wei Xu (ORCID: https://orcid.org/0000-0001-8619-6953)
- Zhen Sun (ORCID: https://orcid.org/0000-0002-7224-3592)
- Yanmin Duan (ORCID: https://orcid.org/0000-0002-5800-0930)
- L. Chen (ORCID: https://orcid.org/0000-0002-7176-4978)
- Jianhua Yang (ORCID: https://orcid.org/0000-0002-7649-8509)
- Yuzhong Qian (ORCID: https://orcid.org/0009-0001-9858-8898)
- Yingying Li (ORCID: https://orcid.org/0000-0002-2978-908X)
- M. Huang
Institutions
- Johns Hopkins University (US)
- Chinese Academy of Sciences (CN)
- Princeton Plasma Physics Laboratory (US)
- Institute of Plasma Physics (CN)
- General Atomics (United States) (US)
Publication Details
- Journal
- Nuclear Fusion
- Published
- 2025-08-29
- DOI
- https://doi.org/10.1088/1741-4326/ae00dc
- Primary Topic
- Magnetic confinement fusion research
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- U.S. Department of Energy
- National Key Research and Development Program of China