2026-10-15T05:00:53Z https://www.scidb.cn/oai

10.57760/sciencedb.05159 2022-10-28T11:24:50Z

2022-10-28 Experimental study of high-k turbulence during an energy confinement degradation phase in EAST ohmic plasmas doi:10.57760/sciencedb.05159 en In this paper, we present experimental studies of both high-kr (k= 10, 18, 26 cm−1, and krho_s = 2, 3.6, 5.2, respectively; kr≈ 0.87k_theta) and high-k_theta (k= 8, 20 cm−1, and krho_s ≈ 0.73, 1.86, respectively;) turbulence behavior during an ohmic energy confinement degradation phase in experimental advanced superconducting tokamak (EAST). High-kr turbulence from density fluctuation at r/a ~ 0.5 and high-k_theta turbulence from densityfluctuation at r/a ~ 0.7–0.97 were measured by tangential and poloidal CO2 laser collective scattering diagnostics, respectively. Note that kr, k_theta, k_perp and rho_s are radial wavenumber, poloidal wavenumber, perpendicular wavenumber and ion gyroradius at electron temperature, respectively. Both high-kr/k_theta turbulence power and energy confinement time tau_E are found to be temporally correlated to line-averaged electron density ne in the plasma current flat-top phase (Ip = 0.4 MA): when the ne shows continuous increase/decrease, the high-kr/k_theta turbulence power increases/decreases correspondingly and the tau_E shows corresponding decrease/increase;the stable ne is related to stable both tau_E and high-kr/k_theta turbulence power. Statistical results of high-kr/k_theta turbulence power versus tau_E further imply that high-kr/k_theta turbulence shows a strong correlation with plasma energy confinement degradation in high line-averaged ne condition, but high-kr and high-k_theta turbulence have relatively weak and no dependence on the transition between linear range tau_E in low-ne condition and energy confinement degradation in the high-ne condition, respectively. Moreover, profiles of electron temperature Te and ne as well as their normalized gradients in a part of high-k_theta density fluctuation measurement region also have been given to qualitatively explain the enhancement of turbulence power with the increase of line-averaged ne. Turbulence; energy confinement; EAST sun peng jun Yadong Li Yang Ren Xiaodong Zhang Guojiang Wu Yumin Wang Yong Liu Tianfu Zhou Xiang Gu Xingqiu Yuan Qing Zang Pan Li Yingjie Chen Yanmin Duan Songtao Mao Bin Zhang Tonghui Shi Haiqing Liu Bo Lv Liqun Hu Jiangang Li PUBLIC https://creativecommons.org/licenses/by/4.0/ dataset http://www.doi.org/https://doi.org/10.1088/1741-4326/ab742e Science Data Bank