Experimental investigation for cross-scale interaction between electron-scale and ion-scale turbulence in Large Helical Device (LHD)
POSTER
Abstract
Some simulation studies indicate that the cross-scale interaction between electron-scale and ion-scale turbulence has a large influence on the turbulent transport in certain Te/Ti region[1]. To study such a cross-scale phenomenon, we observed electron-scale and ion-scale turbulence in combination with millimeter-wave backscattering system[2] and Doppler backscattering system. To obtain a significant change in Te/Ti, we performed several ECH power scan experiments. As a result, we successfully observed electron-scale (ρik⊥ ~ 5) and ion-scale (ρik⊥ ~ 0.5) turbulence simultaneously at the same position with significant change in Te and constant Ti. The electron-scale turbulence intensity is negatively correlated with the ion-scale turbulence intensity in certain Te/Ti region, while it is positively correlated in the other region. We will discuss the results of more detailed correlation analysis at the conference.
[1] S. Maeyama et al 2022 Nat. Commun. 13:3166
[2] T. Tokuzawa et al 2021 Rev. Sci. Instrum. 92 043536
[1] S. Maeyama et al 2022 Nat. Commun. 13:3166
[2] T. Tokuzawa et al 2021 Rev. Sci. Instrum. 92 043536
*This work was partially supported in part by KAKENHI (Nos. 23K25858, 23H01161, 21H04973, and 19H01880), by a budgetary Grant-in-Aid from the NIFS LHD project under the auspices of the NIFS Collaboration Research Program (ULPP027, KIPP019, and LHD115), and by the collaboration programs of the RIAM of Kyushu University. Additional support was provided by Japan/U.S. Cooperation in Fusion Research and 11 Development and SOKENDAI Student Dispatch Program.
Presenters
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Tatsuhiro Nasu
- SOEKNDAI, The Graduate University for Advanced Studies