| Autor: |
Hong, R., Rhodes, T. L., Ren, Y., Diamond, P. H., Jian, X., Zeng, L., Barada, K., Yan, Z., McKee, G. R. |
| Rok vydání: |
2023 |
| Předmět: |
|
| Zdroj: |
Physics of Plasmas 30, 072512 (2023) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1063/5.0148172 |
| Popis: |
A dimensionless collisionality scan has been performed in H-mode plasmas on DIII-D tokamak, with detailed measurements of intermediate-to-high wavenumber turbulence using Doppler backscattering systems. It is found that the shorter wavelength turbulence develops into spatially asymmetric turbulent structures with a long-radial-range correlation (LRRC) in the mid-radius region of high-collisionality discharges. Linear \textsc{cgyro} simulations indicate that the underlying turbulence is likely driven by the electron-temperature-gradient (ETG) mode. The LRRC transport events are highly intermittent and show a power spectrum of \(S_{\tilde{n}}(k_\perp) \propto k^{-1}_\perp\) for density fluctuations, which is often associated with self-organized criticality. The magnitude and the radial scale of those turbulent structures increase significantly when the $E_{r}\times B$ mean flow shearing rate decreases. The enhanced LRRC transport events appear to be correlated with the degraded energy confinement time. The emergence of such LRRC transport events may serve as a candidate explanation for the degrading nature of \emph{H}-mode core plasma confinement at high collisionality. |
| Databáze: |
arXiv |
| Externí odkaz: |
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