SOL width broadening by spreading of pedestal turbulence

Chu, Xu; Diamond, P. H.; Guo, Zhibin

doi:10.1088/1741-4326/ac4f9f

Title: SOL width broadening by spreading of pedestal turbulence

Journal Article · 05 April 2022 · Nuclear Fusion

DOI: https://doi.org/10.1088/1741-4326/ac4f9f · OSTI ID:1861491

^[1];

^[2]; Guo, Zhibin ^[3]

Univ. of Chinese Academy of Sciences, Beijing (China); Princeton Univ., NJ (United States)
Univ. of California San Diego, La Jolla, CA (United States)
Peking Univ., Beijing (China)

The pedestal turbulence intensity required to convert the thin, laminar H-mode scrape-off layer (SOL) to a broad turbulent SOL is calculated using the theory of turbulence spreading. A lower bound on the pedestal turbulence level to exceed the neoclassical heuristic drift (HD) width is derived. A reduced model of SOL turbulence spreading is used to determine the SOL width as a function of intensity flux from the pedestal to the SOL. The cross-over value for exceeding the HD model width is then calculated. We determine the pedestal turbulence levels—and the critical scalings thereof—required to achieve this level of broadening. Both drift wave and ballooning mode turbulence are considered. Here, a sensitivity analysis reveals that the key competition is that between spreading and linear E × B shear damping. The required pedestal turbulence levels scale with ρ/R.

View Accepted Manuscript (DOE)

Cite

Export

Save

Research Organization:: Univ. of California, San Diego, CA (United States)

Sponsoring Organization:: USDOE

Grant/Contract Number:: FG02-04ER54738

OSTI ID:: 1861491

Journal Information:: Nuclear Fusion, Vol. 62, Issue 6; ISSN 0029-5515

Publisher:: IOP ScienceCopyright Statement

Country of Publication:: United States

Language:: English

References (25)

The dependence of divertor power sharing on magnetic flux balance in near double-null configurations on Alcator C-Mod Brunner, D.; Kuang, A. Q.; LaBombard, B. Nuclear Fusion, Vol. 58, Issue 7 https://doi.org/10.1088/1741-4326/aac006	journal	May 2018
Spatial redistribution of turbulent and mean kinetic energy Manz, P.; Xu, M.; Fedorczak, N. Physics of Plasmas, Vol. 19, Issue 1 https://doi.org/10.1063/1.3676634	journal	January 2012
Mesoscopic Transport Events and the Breakdown of Fick’s Law for Turbulent Fluxes Hahm, T. S.; Diamond, P. H. Journal of the Korean Physical Society, Vol. 73, Issue 6 https://doi.org/10.3938/jkps.73.747	journal	September 2018
Effect of edge turbulent transport on scrape-off layer width on HL-2A tokamak Wu, Ting; Xu, Min; Nie, Lin Plasma Science and Technology, Vol. 23, Issue 2 https://doi.org/10.1088/2058-6272/abd6b7	journal	January 2021
Simulations of tokamak boundary plasma turbulence transport in setting the divertor heat flux width Xu, X. Q.; Li, N. M.; Li, Z. Y. Nuclear Fusion, Vol. 59, Issue 12 https://doi.org/10.1088/1741-4326/ab430d	journal	October 2019
Fluctuations and anomalous transport in tokamaks Wootton, A. J.; Carreras, B. A.; Matsumoto, H. Physics of Fluids B: Plasma Physics, Vol. 2, Issue 12 https://doi.org/10.1063/1.859358	journal	December 1990
L-mode-edge negative triangularity tokamak reactor Kikuchi, M.; Takizuka, T.; Medvedev, S. Nuclear Fusion, Vol. 59, Issue 5 https://doi.org/10.1088/1741-4326/ab076d	journal	April 2019
Physics of turbulence spreading and explicit nonlocality Yan, Qinghao; Diamond, P. H. Plasma Physics and Controlled Fusion, Vol. 63, Issue 8 https://doi.org/10.1088/1361-6587/ac0a3c	journal	June 2021
Edge transport studies in the edge and scrape-off layer of the National Spherical Torus Experiment with Langmuir probes Boedo, J. A.; Myra, J. R.; Zweben, S. Physics of Plasmas, Vol. 21, Issue 4 https://doi.org/10.1063/1.4873390	journal	April 2014
Grassy-ELM regime with edge resonant magnetic perturbations in fully noninductive plasmas in the DIII-D tokamak Nazikian, R.; Petty, C. C.; Bortolon, A. Nuclear Fusion, Vol. 58, Issue 10 https://doi.org/10.1088/1741-4326/aad20d	journal	July 2018
Signatures of turbulence spreading during the H–L back-transition in TJ-II plasmas Estrada, T.; Hidalgo, C.; Happel, T. Nuclear Fusion, Vol. 51, Issue 3 https://doi.org/10.1088/0029-5515/51/3/032001	journal	February 2011
Gyrokinetic projection of the divertor heat-flux width from present tokamaks to ITER Chang, C. S.; Ku, S.; Loarte, A. Nuclear Fusion, Vol. 57, Issue 11 https://doi.org/10.1088/1741-4326/aa7efb	journal	August 2017
Different responses of the Rayleigh–Taylor type and resistive drift wave instabilities to the velocity shear Zhang, Y.; Krasheninnikov, S. I.; Smolyakov, A. I. Physics of Plasmas, Vol. 27, Issue 2 https://doi.org/10.1063/1.5130409	journal	February 2020
Heuristic drift-based model of the power scrape-off width in low-gas-puff H-mode tokamaks Goldston, R. J. Nuclear Fusion, Vol. 52, Issue 1 https://doi.org/10.1088/0029-5515/52/1/013009	journal	December 2011
The impact of edge radial electric fields on edge–scrape-off layer coupling in the TJ-II stellarator Grenfell, G.; van Milligen, B. Ph.; Losada, U. Nuclear Fusion, Vol. 60, Issue 1 https://doi.org/10.1088/1741-4326/ab538c	journal	November 2019
Scaling of the tokamak near the scrape-off layer H-mode power width and implications for ITER Eich, T.; Leonard, A. W.; Pitts, R. A. Nuclear Fusion, Vol. 53, Issue 9 https://doi.org/10.1088/0029-5515/53/9/093031	journal	August 2013
Stationary QH-mode plasmas with high and wide pedestal at low rotation on DIII-D Chen, Xi; Burrell, K. H.; Osborne, T. H. Nuclear Fusion, Vol. 57, Issue 2 https://doi.org/10.1088/0029-5515/57/2/022007	journal	September 2016
Scrape-off layer (SOL) power width scaling and correlation between SOL and pedestal gradients across L, I and H-mode plasmas at ASDEX Upgrade Silvagni, D.; Eich, T.; Faitsch, M. Plasma Physics and Controlled Fusion, Vol. 62, Issue 4 https://doi.org/10.1088/1361-6587/ab74e8	journal	February 2020
Radial transport of fluctuation energy in a two-field model of drift-wave turbulence Gürcan, Ö. D.; Diamond, P. H.; Hahm, T. S. Physics of Plasmas, Vol. 13, Issue 5 https://doi.org/10.1063/1.2180668	journal	May 2006
Influence of sheared poloidal rotation on edge turbulence Biglari, H.; Diamond, P. H.; Terry, P. W. Physics of Fluids B: Plasma Physics, Vol. 2, Issue 1 https://doi.org/10.1063/1.859529	journal	January 1990
Origin and turbulence spreading of plasma blobs Manz, P.; Ribeiro, T. T.; Scott, B. D. Physics of Plasmas, Vol. 22, Issue 2 https://doi.org/10.1063/1.4908272	journal	February 2015
Nonlocal properties of gyrokinetic turbulence and the role of E×B flow shear Wang, W. X.; Hahm, T. S.; Lee, W. W. Physics of Plasmas, Vol. 14, Issue 7 https://doi.org/10.1063/1.2750647	journal	July 2007
Front propagation and critical gradient transport models Garbet, X.; Sarazin, Y.; Imbeaux, F. Physics of Plasmas, Vol. 14, Issue 12 https://doi.org/10.1063/1.2824375	journal	December 2007
Dynamics of turbulence spreading in magnetically confined plasmas Gürcan, Ö. D.; Diamond, P. H.; Hahm, T. S. Physics of Plasmas, Vol. 12, Issue 3 https://doi.org/10.1063/1.1853385	journal	March 2005
Cross-field blob transport in tokamak scrape-off-layer plasmas D’Ippolito, D. A.; Myra, J. R.; Krasheninnikov, S. I. Physics of Plasmas, Vol. 9, Issue 1 https://doi.org/10.1063/1.1426394	journal	January 2002