(EX/C3-4) Progress towards Steady-state Operation and Real Time Control of Internal Transport Barriers in JET
X. Litaudon1),
A. Bécoulet1),
F. Crisanti2),
R.C. Wolf3),
Yu.F. Baranov4),
E. Barbato2),
M. Bécoulet1),
R. Budny5),
C. Castaldo2),
R. Cesario2),
C.D. Challis4),
G.D. Conway6),
M.R. De Baar7),
P. De Vries7),
R. Dux6),
L.G. Eriksson1),
B. Esposito2),
R. Felton4),
C. Fourment1),
D. Frigione2),
X. Garbet1),
R. Giannella1),
C. Giroud7),
G. Gorini8),
N.C. Hawkes4),
T. Hellsten9),
T.C. Hender4),
P. Hennequin1),
G.M.D. Hogeweij7),
G.T.A. Huysmans1),
F. Imbeaux1),
E. Joffrin1),
P.J. Lomas4),
Ph Lotte1),
P. Maget1),
J. Mailloux4),
P. Mantica8),
M.J. Mantsinen10),
D. Mazon1),
D. Moreau1),
V. Parail4),
V. Pericoli2),
E. Rachlew9),
M. Riva2),
F. Rimini1),
Y. Sarazin1),
B.C. Stratton5),
T.J.J. Tala10),
G. Tresset1),
O. Tudisco2),
L. Zabeo1),
K-D. Zastrow4),
JET EFDA Contributors
1) Association Euratom CEA-FRANCE, St Paul Lez Durance, France
2) Associazione EURATOM-ENEA sulla Fusione, Centre Ricerche Frascati, Italy
3) Institut für Plasmaphysik, Association EURATOM-FZJ, Jülich, Germany
4) UKAEA-EURATOM Association, Culham Science Centre, Abingdon, UK
5) Princeton Plasma Physics Laboratory, Princeton, USA
6) Max-Planck-Institut für Plasmaphysik, EURATOM-Assoziation, Garching, Germany
7) Associatie EURATOM-FOM, TEC Cluster, Nieuwegein, The Netherlands
8) Instituto di Fisica del Plasma, EURATOM-ENEA-CNR Association, Milan, Italy
9) Alfven Laboratory, KTH, Association EURATOM/VR, Stockholm, Sweden
10) Association EURATOM-TEKES, VTT Chemical Technology, Finland
Abstract. In JET advanced tokamak research mainly focuses on plasmas with
internal transport barriers (ITBs), generated by modifications of the
current profile. The formerly developed optimised shear regime with low
magnetic shear in the plasma center has been extended to deeply reversed
magnetic shear configurations. ITBs occur at much lower access powers. The
achievement of high fusion performance is reported in deeply reversed
magnetic shear configuration. The generation of plasmas with wide ITBs in
this configuration has allowed an extension of the accessible normalised
toroidal beta at high magnetic field. We report on the successful
sustainement and control of the electron and ion ITB in full current drive
operation with a large fraction of bootstrap current. Progress towards the
steady state capability of ITB plasmas includes techniques to avoid strong
ELM activity and the newly developed real time control of the local ITB
strength. Thanks to the real time control of the ITB characteristics the
improved confinement state is maintained in a more reproducible and stable
manner in quasi-stationary conditions.
IAEA 2003
