Stability and Transport of Gyrokinetic Critical Pedestals

Fuente: arXiv
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Main Authors: Parisi, J. F., Nelson, A. O., Guttenfelder, W., Gaur, R., Berkery, J. W., Kaye, S. M., Barada, K., Clauser, C., Diallo, A., Hatch, D. R., Kleiner, A., Lampert, M., Macwan, T., Menard, J. E.
Format: Preprint
Published: 2024
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author Parisi, J. F.
Nelson, A. O.
Guttenfelder, W.
Gaur, R.
Berkery, J. W.
Kaye, S. M.
Barada, K.
Clauser, C.
Diallo, A.
Hatch, D. R.
Kleiner, A.
Lampert, M.
Macwan, T.
Menard, J. E.
author_facet Parisi, J. F.
Nelson, A. O.
Guttenfelder, W.
Gaur, R.
Berkery, J. W.
Kaye, S. M.
Barada, K.
Clauser, C.
Diallo, A.
Hatch, D. R.
Kleiner, A.
Lampert, M.
Macwan, T.
Menard, J. E.
contents A gyrokinetic threshold model for pedestal width-height scaling prediction is applied to multiple devices and to a shaping and aspect-ratio scan giving $Δ_{\mathrm{ped}} = 0.92 A^{1.04} κ^{-1.24} 0.38^δ β_{θ,\mathrm{ped}}^{1.05}$ for pedestal width $Δ_{\mathrm{ped}}$, aspect-ratio $A$, elongation $κ$, triangularity $δ$, and normalized pedestal height $β_{θ,\mathrm{ped}}$. We also find a width-transport scaling $Δ_{\mathrm{ped} } = 0.028 \left(q_e/Γ_e - 1.7 \right)^{1.5} \sim η_e ^{1.5}$ where $q_e$ and $Γ_e$ are turbulent electron heat and particle fluxes and $η_e = \nabla \ln T_e / \nabla \ln n_e$ for electron temperature $T_e$ and density $n_e$. Pedestals close to those limited by kinetic-ballooning-modes (KBMs) have modified turbulent transport properties compared to strongly driven KBMs. The role of flow shear is studied as a width-height scaling constraint and pedestal saturation mechanism for a standard and wide pedestal discharge.
format Preprint
id arxiv_https___arxiv_org_abs_2401_14260
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Stability and Transport of Gyrokinetic Critical Pedestals
Parisi, J. F.
Nelson, A. O.
Guttenfelder, W.
Gaur, R.
Berkery, J. W.
Kaye, S. M.
Barada, K.
Clauser, C.
Diallo, A.
Hatch, D. R.
Kleiner, A.
Lampert, M.
Macwan, T.
Menard, J. E.
Plasma Physics
A gyrokinetic threshold model for pedestal width-height scaling prediction is applied to multiple devices and to a shaping and aspect-ratio scan giving $Δ_{\mathrm{ped}} = 0.92 A^{1.04} κ^{-1.24} 0.38^δ β_{θ,\mathrm{ped}}^{1.05}$ for pedestal width $Δ_{\mathrm{ped}}$, aspect-ratio $A$, elongation $κ$, triangularity $δ$, and normalized pedestal height $β_{θ,\mathrm{ped}}$. We also find a width-transport scaling $Δ_{\mathrm{ped} } = 0.028 \left(q_e/Γ_e - 1.7 \right)^{1.5} \sim η_e ^{1.5}$ where $q_e$ and $Γ_e$ are turbulent electron heat and particle fluxes and $η_e = \nabla \ln T_e / \nabla \ln n_e$ for electron temperature $T_e$ and density $n_e$. Pedestals close to those limited by kinetic-ballooning-modes (KBMs) have modified turbulent transport properties compared to strongly driven KBMs. The role of flow shear is studied as a width-height scaling constraint and pedestal saturation mechanism for a standard and wide pedestal discharge.
title Stability and Transport of Gyrokinetic Critical Pedestals
topic Plasma Physics
url https://arxiv.org/abs/2401.14260