Drift wave turbulence and transport analysis of hot ion L-mode plasma with fishbone instability on the HL-3 tokamak
Abstract
An integrated analysis of the HL-3 hot-ion L-mode (shot \#11972, Ti/Te≈3, Ti(0)≈9.8\,keV) establishes the cross-scale coupling by which a single m=1,n=1 fishbone mode governs both toroidal rotation and ion-scale drift-wave turbulence. Multi-diagnostic measurements, OMFIT integrated modeling, and TGLF quasilinear simulations show that a steep fast-ion pressure gradient under 2.5\,MW co-injected NBI excites the fishbone. Its outward redistribution of resonant fast ions decouples the NBI torque, and the sawtooth crash it triggers collapses the rotation from above $100$ to $60$\,krad/s. The same fast ions that drive the fishbone also stabilize ion-scale ITG/TEM turbulence, so their redistribution removes the ITG stabilization carried by the high temperature ratio, fast-ion dilution, and E× B shear, and erodes the internal transport barrier. Two-dimensional flux and one-dimensional eigenvalue scans confirm that the high temperature ratio and the fast-ion population together suppress particle, energy, and momentum transport. These findings close one cross-scale coupling loop spanning MHD, fast-ion transport and microturbulence, in which one mode drives both momentum balance and turbulence stability. The results offer a predictive framework for fast-ion confinement and rotation sustainment in the upcoming deuterium tritium phase, and for burning plasmas where alpha particles likewise drive MHD activity and damp turbulence.
Related
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BibTeX
@misc{shu2026drift,
title = {{Drift wave turbulence and transport analysis of hot ion L-mode plasma with fishbone instability on the HL-3 tokamak}},
author = {Y. K. Shu and W. Chen and Z. J. Li and S. Xu and Y. F. Liu and B. L. Hao and Z. Wang and D. L. Yu and S. S. Yang and W. Y. Zhai and X. L. Zhu and P. W. Shi and X. L. Xu and T. Wu and Z. B. Shi and HL-3 Team},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.35072},
eprint = {2610.35072},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.35072},
}
RIS
TY - UNPB
TI - Drift wave turbulence and transport analysis of hot ion L-mode plasma with fishbone instability on the HL-3 tokamak
AU - Y. K. Shu
AU - W. Chen
AU - Z. J. Li
AU - S. Xu
AU - Y. F. Liu
AU - B. L. Hao
AU - Z. Wang
AU - D. L. Yu
AU - S. S. Yang
AU - W. Y. Zhai
AU - X. L. Zhu
AU - P. W. Shi
AU - X. L. Xu
AU - T. Wu
AU - Z. B. Shi
AU - HL-3 Team
PY - 2026
DA - 2026/10/26
PB - arXiv
DO - 10.48550/arxiv.2610.35072
UR - https://arxiv.org/abs/2610.35072
AB - An integrated analysis of the HL-3 hot-ion L-mode (shot \#11972, T_i/T_e≈3, T_i(0)≈9.8\,keV) establishes the cross-scale coupling by which a single m=1,n=1 fishbone mode governs both toroidal rotation and ion-scale drift-wave turbulence. Multi-diagnostic measurements, OMFIT integrated modeling, and TGLF quasilinear simulations show that a steep fast-ion pressure gradient under 2.5\,MW co-injected NBI excites the fishbone. Its outward redistribution of resonant fast ions decouples the NBI torque, and the sawtooth crash it triggers collapses the rotation from above $100$ to $60$\,krad/s. The same fast ions that drive the fishbone also stabilize ion-scale ITG/TEM turbulence, so their redistribution removes the ITG stabilization carried by the high temperature ratio, fast-ion dilution, and E× B shear, and erodes the internal transport barrier. Two-dimensional flux and one-dimensional eigenvalue scans confirm that the high temperature ratio and the fast-ion population together suppress particle, energy, and momentum transport. These findings close one cross-scale coupling loop spanning MHD, fast-ion transport and microturbulence, in which one mode drives both momentum balance and turbulence stability. The results offer a predictive framework for fast-ion confinement and rotation sustainment in the upcoming deuterium tritium phase, and for burning plasmas where alpha particles likewise drive MHD activity and damp turbulence.
ER -