Perturbative studies of toroidal momentum transport using neutral beam injection modulation in the Joint European Torus: Experimental results, analysis methodology, and first principles modeling

JET-EFDA collaborators

Research output: Contribution to journalArticleScientificpeer-review

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Abstract

Perturbative experiments have been carried out in the Joint European Torus [Fusion Sci. Technol. 53(4) (2008)] in order to identify the diffusive and convective components of toroidal momentum transport. The torque source was modulated either by modulating tangential neutral beam power or by modulating in antiphase tangential and normal beams to produce a torque perturbation in the absence of a power perturbation. The resulting periodic perturbation in the toroidal rotation velocity was modeled using time-dependent transport simulations in order to extract empirical profiles of momentum diffusivity and pinch. Details of the experimental technique, data analysis, and modeling are provided. The momentum diffusivity in the core region (0.2 < ρ < 0.8) was found to be close to the ion heat diffusivity (χϕi ∼ 0.7–1.7) and a significant inward momentum convection term, up to 20 m/s, was found, leading to an effective momentum diffusivity significantly lower than the ion heat diffusivity (χϕeffieff ∼ 0.4). These results have significant implications on the prediction of toroidal rotation velocities in future tokamaks and are qualitatively consistent with recent developments in momentum transport theory. Detailed quantitative comparisons with the theoretical predictions of the linear gyrokinetic code GKW [A. G. Peeters et al., Comput. Phys. Commun. 180, 2650 (2009)] and of the quasilinear fluid Weiland model [J. Weiland, Collective Modes in Inhomogeneous Plasmas (IOP, Bristol, 2000)] are presented for two analyzed discharges.
Original languageEnglish
Article number092505
Number of pages20
JournalPhysics of Plasmas
Volume17
Issue number9
DOIs
Publication statusPublished - 2010
MoE publication typeA1 Journal article-refereed

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Joint European Torus
beam injection
neutral beams
diffusivity
methodology
momentum
modulation
perturbation
torque
heat
transport theory
predictions
ions
convection
fusion
fluids
profiles

Keywords

  • pinch effect
  • plasma beam injection heating
  • plasma kinetic theory
  • plasma magnetohydrodynamics
  • plasma simulation
  • plasma toroidal confinement
  • plasma transport processes
  • Tokamak devices

Cite this

@article{2b2b77c448584fb9800f3492e866c6da,
title = "Perturbative studies of toroidal momentum transport using neutral beam injection modulation in the Joint European Torus: Experimental results, analysis methodology, and first principles modeling",
abstract = "Perturbative experiments have been carried out in the Joint European Torus [Fusion Sci. Technol. 53(4) (2008)] in order to identify the diffusive and convective components of toroidal momentum transport. The torque source was modulated either by modulating tangential neutral beam power or by modulating in antiphase tangential and normal beams to produce a torque perturbation in the absence of a power perturbation. The resulting periodic perturbation in the toroidal rotation velocity was modeled using time-dependent transport simulations in order to extract empirical profiles of momentum diffusivity and pinch. Details of the experimental technique, data analysis, and modeling are provided. The momentum diffusivity in the core region (0.2 < ρ < 0.8) was found to be close to the ion heat diffusivity (χϕ/χi ∼ 0.7–1.7) and a significant inward momentum convection term, up to 20 m/s, was found, leading to an effective momentum diffusivity significantly lower than the ion heat diffusivity (χϕeff/χieff ∼ 0.4). These results have significant implications on the prediction of toroidal rotation velocities in future tokamaks and are qualitatively consistent with recent developments in momentum transport theory. Detailed quantitative comparisons with the theoretical predictions of the linear gyrokinetic code GKW [A. G. Peeters et al., Comput. Phys. Commun. 180, 2650 (2009)] and of the quasilinear fluid Weiland model [J. Weiland, Collective Modes in Inhomogeneous Plasmas (IOP, Bristol, 2000)] are presented for two analyzed discharges.",
keywords = "pinch effect, plasma beam injection heating, plasma kinetic theory, plasma magnetohydrodynamics, plasma simulation, plasma toroidal confinement, plasma transport processes, Tokamak devices",
author = "P. Mantica and Tuomas Tala and Ferreira, {J. S.} and Peeters, {A. G.} and Antti Salmi and D. Strintzi and J. Weiland and M. Brix and C. Giroud and G. Corrigan and V. Naulin and G. Tardini and K.-D. Zastrow and {JET-EFDA collaborators}",
year = "2010",
doi = "10.1063/1.3480640",
language = "English",
volume = "17",
journal = "Physics of Plasmas",
issn = "1527-2419",
publisher = "American Institute of Physics AIP",
number = "9",

}

Perturbative studies of toroidal momentum transport using neutral beam injection modulation in the Joint European Torus : Experimental results, analysis methodology, and first principles modeling. / JET-EFDA collaborators.

In: Physics of Plasmas, Vol. 17, No. 9, 092505, 2010.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Perturbative studies of toroidal momentum transport using neutral beam injection modulation in the Joint European Torus

T2 - Experimental results, analysis methodology, and first principles modeling

AU - Mantica, P.

AU - Tala, Tuomas

AU - Ferreira, J. S.

AU - Peeters, A. G.

AU - Salmi, Antti

AU - Strintzi, D.

AU - Weiland, J.

AU - Brix, M.

AU - Giroud, C.

AU - Corrigan, G.

AU - Naulin, V.

AU - Tardini, G.

AU - Zastrow, K.-D.

AU - JET-EFDA collaborators

PY - 2010

Y1 - 2010

N2 - Perturbative experiments have been carried out in the Joint European Torus [Fusion Sci. Technol. 53(4) (2008)] in order to identify the diffusive and convective components of toroidal momentum transport. The torque source was modulated either by modulating tangential neutral beam power or by modulating in antiphase tangential and normal beams to produce a torque perturbation in the absence of a power perturbation. The resulting periodic perturbation in the toroidal rotation velocity was modeled using time-dependent transport simulations in order to extract empirical profiles of momentum diffusivity and pinch. Details of the experimental technique, data analysis, and modeling are provided. The momentum diffusivity in the core region (0.2 < ρ < 0.8) was found to be close to the ion heat diffusivity (χϕ/χi ∼ 0.7–1.7) and a significant inward momentum convection term, up to 20 m/s, was found, leading to an effective momentum diffusivity significantly lower than the ion heat diffusivity (χϕeff/χieff ∼ 0.4). These results have significant implications on the prediction of toroidal rotation velocities in future tokamaks and are qualitatively consistent with recent developments in momentum transport theory. Detailed quantitative comparisons with the theoretical predictions of the linear gyrokinetic code GKW [A. G. Peeters et al., Comput. Phys. Commun. 180, 2650 (2009)] and of the quasilinear fluid Weiland model [J. Weiland, Collective Modes in Inhomogeneous Plasmas (IOP, Bristol, 2000)] are presented for two analyzed discharges.

AB - Perturbative experiments have been carried out in the Joint European Torus [Fusion Sci. Technol. 53(4) (2008)] in order to identify the diffusive and convective components of toroidal momentum transport. The torque source was modulated either by modulating tangential neutral beam power or by modulating in antiphase tangential and normal beams to produce a torque perturbation in the absence of a power perturbation. The resulting periodic perturbation in the toroidal rotation velocity was modeled using time-dependent transport simulations in order to extract empirical profiles of momentum diffusivity and pinch. Details of the experimental technique, data analysis, and modeling are provided. The momentum diffusivity in the core region (0.2 < ρ < 0.8) was found to be close to the ion heat diffusivity (χϕ/χi ∼ 0.7–1.7) and a significant inward momentum convection term, up to 20 m/s, was found, leading to an effective momentum diffusivity significantly lower than the ion heat diffusivity (χϕeff/χieff ∼ 0.4). These results have significant implications on the prediction of toroidal rotation velocities in future tokamaks and are qualitatively consistent with recent developments in momentum transport theory. Detailed quantitative comparisons with the theoretical predictions of the linear gyrokinetic code GKW [A. G. Peeters et al., Comput. Phys. Commun. 180, 2650 (2009)] and of the quasilinear fluid Weiland model [J. Weiland, Collective Modes in Inhomogeneous Plasmas (IOP, Bristol, 2000)] are presented for two analyzed discharges.

KW - pinch effect

KW - plasma beam injection heating

KW - plasma kinetic theory

KW - plasma magnetohydrodynamics

KW - plasma simulation

KW - plasma toroidal confinement

KW - plasma transport processes

KW - Tokamak devices

U2 - 10.1063/1.3480640

DO - 10.1063/1.3480640

M3 - Article

VL - 17

JO - Physics of Plasmas

JF - Physics of Plasmas

SN - 1527-2419

IS - 9

M1 - 092505

ER -