Evolution of the radial electric field in a JET H-mode plasmaY. Andrew1, 2, N. C. Hawkes1, 2, T. Biewer1, 3, K. Crombe1, 4, D. Keeling1, 2, E. de la Luna1, 5, C. Giroud1, 2, A. Korotkov1, 2, A. Meigs1, 2, A. Murari1, 6, I. Nunes1, 7, R. Sartori1, 8, T. Tala1, 9 and JET-EFDA contributors1
1 JET-EFDA, Culham Science Centre - Abingdon, OX14 3DB, UK, EU
2 Euratom/UKAEA Fusion Association, Culham Science Centre - Abingdon, OX14 3DB, UK, EU
3 Oak Ridge National Laboratory - Oak Ridge, TN 37831, USA
4 Department of Applied Physics, Ghent University - Belgium, EU
5 Asociasion EURATOM-CIEMAT para Fusion, CIEMAT - Madrid, Spain, EU
6 Consorzio RFX, ENEA-Euratom Association - Padua, Italy, EU
7 Associação EURATOM/IST, Centrode Fusão Nuclear - Lisbon, Portugal, EU
8 EFDA CSU - Boltzmannstrasse 2, 85748 Garching, Germany, EU
9 Association EURATOM-Tekes, VTT - P.O. Box 1000, FIN-02044 VTT, Finland, EU
received 27 March 2008; accepted in final form 20 May 2008; published July 2008
published online 16 June 2008
Results from recent measurements of carbon impurity ion toroidal and poloidal rotation velocities, ion temperature, ion density and the resulting radial electric field (Er) profiles are presented from an evolving Joint European Torus (JET) tokamak plasma over a range of energy and particle confinement regimes. Significant levels of edge plasma poloidal rotation velocity have been measured for the first time on JET, with maximum values of 9 km s-1. Such values of poloidal rotation provide an important contribution to the total edge plasma Er profiles. Large values of shear in the measured Er profiles are observed to arise as a consequence of the presence of the edge transport barrier (ETB) and do not appear to be necessary for their formation or destruction. These results have an important impact on potential mechanisms for transport barrier triggering and sustainment in present-day and future high-performance fusion plasmas.
52.30.-q - Plasma dynamics and flow.
© EPLA 2008