Radial electric field in JET advanced tokamak scenarios with toroidal field ripple

K. Crombé, Y. Andrew, T.M. Biewer, E. Blanco, P.C. De Vries, C. Giroud, N.C. Hawkes, A. Meigs, Tuomas Tala, M. Von Hellermann, K.-D. Zastrow, J. Efda

Research output: Contribution to journalArticleScientificpeer-review

12 Citations (Scopus)

Abstract

A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (vθ) in the ITB region is measured to be of the order of a few tens of km s−1, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of vθ is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (Er), with the largest gradient in Er measured in the radial region coinciding with the ITB.
Original languageEnglish
JournalPlasma Physics and Controlled Fusion
Volume51
Issue number5
DOIs
Publication statusPublished - 2009
MoE publication typeA1 Journal article-refereed

Fingerprint

ripples
Electric fields
ion temperature
electric fields
Plasmas
Ions
Electric field measurement
Thermal gradients
Ion exchange
charge exchange
Impurities
temperature gradients
Temperature
velocity distribution
shear
impurities
gradients
profiles
predictions
Experiments

Keywords

  • plasma toroidal confinement
  • toroidal field ripple
  • plasma
  • plasma transport processes
  • plasma turbulence
  • Tokamak
  • JET

Cite this

Crombé, K., Andrew, Y., Biewer, T. M., Blanco, E., De Vries, P. C., Giroud, C., ... Efda, J. (2009). Radial electric field in JET advanced tokamak scenarios with toroidal field ripple. Plasma Physics and Controlled Fusion, 51(5). https://doi.org/10.1088/0741-3335/51/5/055005
Crombé, K. ; Andrew, Y. ; Biewer, T.M. ; Blanco, E. ; De Vries, P.C. ; Giroud, C. ; Hawkes, N.C. ; Meigs, A. ; Tala, Tuomas ; Von Hellermann, M. ; Zastrow, K.-D. ; Efda, J. / Radial electric field in JET advanced tokamak scenarios with toroidal field ripple. In: Plasma Physics and Controlled Fusion. 2009 ; Vol. 51, No. 5.
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title = "Radial electric field in JET advanced tokamak scenarios with toroidal field ripple",
abstract = "A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (vθ) in the ITB region is measured to be of the order of a few tens of km s−1, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of vθ is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (Er), with the largest gradient in Er measured in the radial region coinciding with the ITB.",
keywords = "plasma toroidal confinement, toroidal field ripple, plasma, plasma transport processes, plasma turbulence, Tokamak, JET",
author = "K. Cromb{\'e} and Y. Andrew and T.M. Biewer and E. Blanco and {De Vries}, P.C. and C. Giroud and N.C. Hawkes and A. Meigs and Tuomas Tala and {Von Hellermann}, M. and K.-D. Zastrow and J. Efda",
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Crombé, K, Andrew, Y, Biewer, TM, Blanco, E, De Vries, PC, Giroud, C, Hawkes, NC, Meigs, A, Tala, T, Von Hellermann, M, Zastrow, K-D & Efda, J 2009, 'Radial electric field in JET advanced tokamak scenarios with toroidal field ripple', Plasma Physics and Controlled Fusion, vol. 51, no. 5. https://doi.org/10.1088/0741-3335/51/5/055005

Radial electric field in JET advanced tokamak scenarios with toroidal field ripple. / Crombé, K.; Andrew, Y.; Biewer, T.M.; Blanco, E.; De Vries, P.C.; Giroud, C.; Hawkes, N.C.; Meigs, A.; Tala, Tuomas; Von Hellermann, M.; Zastrow, K.-D.; Efda, J.

In: Plasma Physics and Controlled Fusion, Vol. 51, No. 5, 2009.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Radial electric field in JET advanced tokamak scenarios with toroidal field ripple

AU - Crombé, K.

AU - Andrew, Y.

AU - Biewer, T.M.

AU - Blanco, E.

AU - De Vries, P.C.

AU - Giroud, C.

AU - Hawkes, N.C.

AU - Meigs, A.

AU - Tala, Tuomas

AU - Von Hellermann, M.

AU - Zastrow, K.-D.

AU - Efda, J.

PY - 2009

Y1 - 2009

N2 - A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (vθ) in the ITB region is measured to be of the order of a few tens of km s−1, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of vθ is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (Er), with the largest gradient in Er measured in the radial region coinciding with the ITB.

AB - A dedicated campaign has been run on JET to study the effect of toroidal field (TF) ripple on plasma performance. Radial electric field measurements from experiments on a series of plasmas with internal transport barriers (ITBs) and different levels of ripple amplitude are presented. They have been calculated from charge exchange measurements of impurity ion temperature, density and rotation velocity profiles, using the force balance equation. The ion temperature and the toroidal and poloidal rotation velocities are compared in plasmas with both reversed and optimized magnetic shear profiles. Poloidal rotation velocity (vθ) in the ITB region is measured to be of the order of a few tens of km s−1, significantly larger than the neoclassical predictions. Increasing levels of the TF ripple are found to decrease the ion temperature gradient in the ITB region, a measure for the quality of the ITB, and the maximum value of vθ is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (Er), with the largest gradient in Er measured in the radial region coinciding with the ITB.

KW - plasma toroidal confinement

KW - toroidal field ripple

KW - plasma

KW - plasma transport processes

KW - plasma turbulence

KW - Tokamak

KW - JET

U2 - 10.1088/0741-3335/51/5/055005

DO - 10.1088/0741-3335/51/5/055005

M3 - Article

VL - 51

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

SN - 0741-3335

IS - 5

ER -