Observation of electron-scale turbulence suppression under weak magnetic shear with neon seeding in EAST plasma
| Autor: | Y.Q. Chu, B.S. Zhang, P. Li, X.D. Yang, H.Q. Liu, Y.X. Jie, C.B. Wu, W.M. Zhang, K.D. Li, T.F. Zhou, L. He, Q. Zang, H. Lian, F.B. Zhong, R.J. Zhu, L. F. Zhang, K. Hanada, the EAST Team |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Nuclear Fusion, Vol 63, Iss 8, p 086021 (2023) |
| Druh dokumentu: | article |
| ISSN: | 1741-4326 0029-5515 |
| DOI: | 10.1088/1741-4326/acdd83 |
| Popis: | Improved confinement caused by Ne injection is investigated in EAST. The safety factor q profile and electron-scale turbulence are studied with a polarimeter-interferometer system and CO _2 laser collective scattering system in a series of Ne injection experiments in EAST. Ne with a suitable injection rate can lead to negative magnetic shear in the plasma core, which promotes electron-scale turbulence suppression. The continuous injection of Ne under the reversed shear condition further reduces the electron-scale turbulence intensity. Core electron temperature increase and confinement improvement are observed. QuaLiKiz is applied to model the influence of an impurity and reversed q on turbulence. The combination of stabilization effects of negative magnetic shear and Ne on turbulence is much stronger than the impurity’s own effect, which could explain the experimentally observed electron temperature ( T _e ) increase and turbulence suppression. Besides, the relationship between pedestal structure induced by Ne injection and lower hybrid wave (LHW)-driven current deposition is discussed. These results provide a new perspective to improve the confinement in the case of Ne injection, i.e. to adjust the Ne injection to modify the ideal plasma equilibrium. |
| Databáze: | Directory of Open Access Journals |
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