Identification of intermittent transport in the scrape-off layer of MAST through high speed imaging

Walkden, N.; Militello, F.; Harrison, James R.; Farley, Tom; Silburn, S.; Young, J.

doi:10.1016/j.nme.2016.10.024

“…Then, the vertical charge separation inside the filaments, caused by magnetic gradients and curvature drifts, generates a vertical electric field that, in turns, gives rise to a radial E × B drift that transports filaments outwards, contributing significantly to the perpendicular transport in the far SOL, flattening the density and pressure profile, and increasing the plasma-wall contact, as experimentally observed in reference [33]. Plasma filaments have been experimentally studied in tokamaks [34][35][36][37][38][39], stellarators [40], reversed field pinch [41], and basic plasma devices [13,[42][43][44].…”

Section: Introductionmentioning

confidence: 93%

Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges

Giacomin

¹

,

Stagni

²

,

Ricci

³

et al. 2021

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Theory-based scaling laws of the near and far scrape-off layer (SOL) widths are analytically derived for L-mode diverted tokamak discharges by using a two-fluid model. The near SOL pressure and density decay lengths are obtained by leveraging a balance among the power source, perpendicular turbulent transport across the separatrix, and parallel losses at the vessel wall, while the far SOL pressure and density decay lengths are derived by using a model of intermittent transport mediated by filaments. The analytical estimates of the pressure decay length in the near SOL is then compared to the results of three-dimensional, flux-driven, global, two-fluid turbulence simulations of L-mode diverted tokamak plasmas, and validated against experimental measurements taken from an experimental multi-machine database of divertor heat flux profiles, showing in both cases a very good agreement. Analogously, the theoretical scaling law for the pressure decay length in the far SOL is compared to simulation results and to experimental measurements in TCV L-mode discharges, pointing out the need of a large multi-machine database for the far SOL decay lengths.

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“…[60,61]. In addition, as it is also experimentally observed [62,63,64,65], turbulence in the far SOL is characterized by intermittent events due to coherent plasma filaments [66].…”

Section: First Simulation Results In An Experimentally-relevant Scenariomentioning

confidence: 61%

The GBS code for the self-consistent simulation of plasma turbulence and kinetic neutral dynamics in the tokamak boundary

Giacomin,

Ricci,

Coroado

et al. 2021

Preprint

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“…[27]. Plasma filaments have been experimentally studied in tokamaks [28][29][30][31], stellarators [32], reversed field pinch [33], and basic plasma devices [10,34,35].…”

Section: Introductionmentioning

confidence: 99%

Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges

Giacomin,

Stagni,

Ricci

et al. 2021

Preprint

0

View full text Add to dashboard Cite

Theory-based scaling laws of the near and far scrape-off layer (SOL) widths are analytically derived for L-mode diverted tokamak discharges by using a two-fluid model. The near SOL pressure and density decay lengths are obtained by leveraging a balance among the power source, perpendicular turbulent transport across the separatrix, and parallel losses at the vessel wall, while the far SOL pressure and density decay lengths are derived by using a model of intermittent transport mediated by filaments. The analytical estimates of the pressure decay length in the near SOL is then compared to the results of three-dimensional, flux-driven, global, two-fluid turbulence simulations of L-mode diverted tokamak plasmas, and validated against experimental measurements taken from an experimental multi-machine database of divertor heat flux profiles, showing in both cases a very good agreement. Analogously, the theoretical scaling law for the pressure decay length in the far SOL is compared to simulation results and to experimental measurements in TCV L-mode discharges, pointing out the need of a large multi-machine database for the far SOL decay lengths.

show abstract

Identification of intermittent transport in the scrape-off layer of MAST through high speed imaging

Cited by 14 publications

References 15 publications

Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges

Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges

The GBS code for the self-consistent simulation of plasma turbulence and kinetic neutral dynamics in the tokamak boundary

Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges

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