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

TitleRadial electric field in JET advanced tokamak scenarios with toroidal field ripple
Publication TypeJournal Article
Year of Publication2009
AuthorsK. Crombe, Y. Andrew, T.M Biewer, E. Blanco, P.C de Vries, C. Giroud, N.C Hawkes, A. Meigs, T. Tala, M. von Hellermann, K.D Zastrow
JournalPlasma Physics and Controlled Fusion
Volume51
Number5
Pagination11
Date PublishedMay
Type of ArticleArticle
ISBN Number0741-3335
Accession NumberISI:000265584300005
KeywordsJOINT EUROPEAN TORUS, TRANSPORT BARRIERS, TURBULENCE
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 (v(theta)) 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 v(theta) is reduced. The poloidal rotation term dominates in the calculations of the total radial electric field (E-r), with the largest gradient in E-r measured in the radial region coinciding with the ITB.

URL<Go to ISI>://000265584300005
Division

Fusion Physics

PID

cb2094624fa307fb491e420d1a4296e6

Alternate TitlePlasma Phys. Control. Fusion

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