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arXiv · 2311.05357

Long radial coherence of electron temperature fluctuations in non-local transport in HL-2A plasmas

Zhongbing Shi·Kairui Fang·Jingchun Li·Xiaolan Zou·Zhaoyang Lu·Jie Wen·Zhanhui Wang·Xuantong Ding·Wei Chen·Zengchen Yang·Min Jiang Xiaoquan Ji·Ruihai Tong·Yonggao Li·Peiwang Shi·Wulyv Zhong·Min Xu
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Abstract

The dynamics of long-wavelength ($k_\theta<1.4 \mathrm{\ cm^{-1}}$), broadband (20-200 kHz) electron temperature fluctuations ($\tilde T_e/T_e$) of plasmas in gas-puff experiments were observed for the first time in HL-2A tokamak. In a relative low density ($n_e(0) \simeq 0.91 \sim 1.20 \times10^{19}/m^3$) scenario, after gas-puffing the core temperature increases and the edge temperature drops. On the contrary, temperature fluctuation drops at the core and increases at the edge. Analyses show the non-local emergence is accompanied with a long radial coherent length of turbulent fluctuations. While in a higher density ($n_e(0) \simeq 1.83 \sim 2.02 \times10^{19}/m^3$) scenario, the phenomena were not observed. Furthermore, compelling evidence indicates that $\textbf{E} \times \textbf{B}$ shear serves as a substantial contributor to this extensive radial interaction. This finding offers a direct explanatory link to the intriguing core-heating phenomenon witnessed within the realm of non-local transport.

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Zhongbing Shi, Kairui Fang, Jingchun Li, Xiaolan Zou, Zhaoyang Lu, Jie Wen, Zhanhui Wang, Xuantong Ding, Wei Chen, Zengchen Yang, Min Jiang Xiaoquan Ji, Ruihai Tong, Yonggao Li, Peiwang Shi, Wulyv Zhong, Min Xu. 2023-11-09. Long radial coherence of electron temperature fluctuations in non-local transport in HL-2A plasmas. https://arxiv.org/abs/2311.05357

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