Measurement of Zero-Frequency Fluctuations Generated by Coupling between Alfvén Modes in the JET Tokamak
We report the first experimental detection of a zero-frequency fluctuation that is pumped by an Alfvén mode in a magnetically confined plasma. Core-localized Alfvén modes of frequency inside the toroidicity-induced gap (and its harmonics) exhibit three-wave coupling interactions with a zero-frequency fluctuation. The observation of the zero-frequency fluctuation is consistent with theoretical and numerical predictions of zonal modes pumped by Alfvén modes, and is correlated with an increase in the deep core ion temperature, temperature gradient, confinement factor H_{89,P}, and a reduction in the main ion heat diffusivity. Despite the energetic particle transport induced by the Alfvén eigenmodes, the generation of a zero-frequency fluctuation that can suppress the turbulence leads to an overall improvement of confinement.
Authors
- M. Dreval (ORCID: https://orcid.org/0000-0003-0482-0981)
- Y. Kazakov (ORCID: https://orcid.org/0000-0001-6316-5441)
- B. Patel (ORCID: https://orcid.org/0000-0003-0121-1187)
- S. Mazzi (ORCID: https://orcid.org/0000-0001-6491-8759)
- Ž. Štancar (ORCID: https://orcid.org/0000-0002-9608-280X)
- V. H. Hall-Chen (ORCID: https://orcid.org/0000-0001-6009-3649)
- F. I. Parra (ORCID: https://orcid.org/0000-0001-9621-7404)
- A. A. Schekochihin (ORCID: https://orcid.org/0000-0003-4421-1128)
- Juan Ruiz Ruiz (ORCID: https://orcid.org/0000-0003-4258-5273)
- Michael Hardman (ORCID: https://orcid.org/0000-0001-5152-3061)
- M. Barnes (ORCID: https://orcid.org/0000-0002-0177-1689)
- J. Garcia
- C. Giroud
- J. C. Hillesheim
Institutions
- Agency for Science, Technology and Research (SG)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Princeton Plasma Physics Laboratory (US)
- Kharkiv Institute of Physics and Technology (UA)
- Kingston College (GB)
- Institute of High Performance Computing (SG)
- University of Oxford (GB)
- Plasma (Russia) (RU)
- Tokamak Energy (United Kingdom) (GB)
- CEA Cadarache (FR)
- Université Bourgogne Franche-Comté (FR)
- National Science Centre (PL)
- Fusion Academy (US)
- United Kingdom Atomic Energy Authority (GB)
Publication Details
- Journal
- Physical Review Letters
- Published
- 2025-03-07
- DOI
- https://doi.org/10.1103/physrevlett.134.095103
- Citations
- 10
- Primary Topic
- Magnetic confinement fusion research
- Type
- article
- Field-Weighted Citation Impact
- 18.70
Funders
- U.S. Department of Energy
- Simons Foundation
- Agency for Science, Technology and Research
- Euratom Research and Training Programme
- Engineering and Physical Sciences Research Council
- Science and Technology Facilities Council