Momentum transport studies in JET H-mode discharges with an enhanced toroidal field ripple

JET-EFDA collaborators

Research output: Contribution to journalArticleScientificpeer-review

15 Citations (Scopus)

Abstract

In this study, enhancement of the toroidal field (TF) ripple has been used as a tool in order to reveal the impact of the momentum pinch on the rotation profiles in H-mode JET discharges. The analysis showed that flatter rotation profiles were obtained in discharges with a high TF ripple, attributed to a smaller inward momentum convection. An average inward momentum pinch of approximately Vp ≈ 3.4 m s−1 and a normalized pinch value of RVp/χ ≈ 6.6 could explain the observation. The data show that the momentum at the edge affects the peaking of the rotation and momentum density profiles. Under the assumption that the heat and momentum diffusivities are equal, an estimate of the levels of the momentum pinch in all discharges in the JET rotation database was made. For H-mode discharge these ranged from 0.3 m s−1 < Vp < 17 m s−1, with 2 < RVp/χ < 10. A larger momentum pinch was found in discharges with a smaller density profile gradient length, i.e. a more peaked density profile.
Original languageEnglish
Article number065004
Number of pages11
JournalPlasma Physics and Controlled Fusion
Volume52
Issue number6
DOIs
Publication statusPublished - 2010
MoE publication typeA1 Journal article-refereed

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ripples
Momentum
momentum
profiles
diffusivity
convection
heat
gradients
augmentation
estimates

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@article{6827d4895f1e472396395d96f536612f,
title = "Momentum transport studies in JET H-mode discharges with an enhanced toroidal field ripple",
abstract = "In this study, enhancement of the toroidal field (TF) ripple has been used as a tool in order to reveal the impact of the momentum pinch on the rotation profiles in H-mode JET discharges. The analysis showed that flatter rotation profiles were obtained in discharges with a high TF ripple, attributed to a smaller inward momentum convection. An average inward momentum pinch of approximately Vp ≈ 3.4 m s−1 and a normalized pinch value of RVp/χ ≈ 6.6 could explain the observation. The data show that the momentum at the edge affects the peaking of the rotation and momentum density profiles. Under the assumption that the heat and momentum diffusivities are equal, an estimate of the levels of the momentum pinch in all discharges in the JET rotation database was made. For H-mode discharge these ranged from 0.3 m s−1 < Vp < 17 m s−1, with 2 < RVp/χ < 10. A larger momentum pinch was found in discharges with a smaller density profile gradient length, i.e. a more peaked density profile.",
author = "{de Vries}, {P. C.} and Versloot, {T. W.} and Antti Salmi and M.-D. Hua and Howell, {D. H.} and C. Giroud and V. Parail and G. Saibene and Tuomas Tala and {JET-EFDA collaborators}",
year = "2010",
doi = "10.1088/0741-3335/52/6/065004",
language = "English",
volume = "52",
journal = "Plasma Physics and Controlled Fusion",
issn = "0741-3335",
publisher = "Institute of Physics IOP",
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}

Momentum transport studies in JET H-mode discharges with an enhanced toroidal field ripple. / JET-EFDA collaborators.

In: Plasma Physics and Controlled Fusion, Vol. 52, No. 6, 065004, 2010.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Momentum transport studies in JET H-mode discharges with an enhanced toroidal field ripple

AU - de Vries, P. C.

AU - Versloot, T. W.

AU - Salmi, Antti

AU - Hua, M.-D.

AU - Howell, D. H.

AU - Giroud, C.

AU - Parail, V.

AU - Saibene, G.

AU - Tala, Tuomas

AU - JET-EFDA collaborators

PY - 2010

Y1 - 2010

N2 - In this study, enhancement of the toroidal field (TF) ripple has been used as a tool in order to reveal the impact of the momentum pinch on the rotation profiles in H-mode JET discharges. The analysis showed that flatter rotation profiles were obtained in discharges with a high TF ripple, attributed to a smaller inward momentum convection. An average inward momentum pinch of approximately Vp ≈ 3.4 m s−1 and a normalized pinch value of RVp/χ ≈ 6.6 could explain the observation. The data show that the momentum at the edge affects the peaking of the rotation and momentum density profiles. Under the assumption that the heat and momentum diffusivities are equal, an estimate of the levels of the momentum pinch in all discharges in the JET rotation database was made. For H-mode discharge these ranged from 0.3 m s−1 < Vp < 17 m s−1, with 2 < RVp/χ < 10. A larger momentum pinch was found in discharges with a smaller density profile gradient length, i.e. a more peaked density profile.

AB - In this study, enhancement of the toroidal field (TF) ripple has been used as a tool in order to reveal the impact of the momentum pinch on the rotation profiles in H-mode JET discharges. The analysis showed that flatter rotation profiles were obtained in discharges with a high TF ripple, attributed to a smaller inward momentum convection. An average inward momentum pinch of approximately Vp ≈ 3.4 m s−1 and a normalized pinch value of RVp/χ ≈ 6.6 could explain the observation. The data show that the momentum at the edge affects the peaking of the rotation and momentum density profiles. Under the assumption that the heat and momentum diffusivities are equal, an estimate of the levels of the momentum pinch in all discharges in the JET rotation database was made. For H-mode discharge these ranged from 0.3 m s−1 < Vp < 17 m s−1, with 2 < RVp/χ < 10. A larger momentum pinch was found in discharges with a smaller density profile gradient length, i.e. a more peaked density profile.

U2 - 10.1088/0741-3335/52/6/065004

DO - 10.1088/0741-3335/52/6/065004

M3 - Article

VL - 52

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

SN - 0741-3335

IS - 6

M1 - 065004

ER -