(OV/4-4) Magnetic Configuration and Transport Interplay in the TJ-II Flexible Heliac Experiment
C. Alejaldre1),
J. Alonso1),
L. Almoguera1),
F. de Aragón1),
E. Ascasíbar1),
A. Baciero1),
R. Balbín1),
E. Blanco1),
M. Blaumoser1),
J. Botija1),
B. Brañas1),
A. Cappa1),
R. Carrasco1),
F. Castejón1),
J.R. Cepero1),
A.A. Chmyga2),
J. Doncel1),
N.B. Dreval2),
S. Eguilior1),
L. Eliseev3),
T. Estrada1),
O. Fedyanin4),
A. Fernández1),
J.M. Fontdecaba5),
C. Fuentes1),
A. García1),
I. García-Cortés1),
B. Gonçalves6),
J. Guasp1),
J. Herranz1),
A. Hidalgo1),
C. Hidalgo1),
J.A. Jiménez1),
I. Kirpitchev1),
S.M. Khrebtov2),
A.D. Komarov2),
A.S. Kozachok2),
L. Krupnik2),
F. Lapayese1),
K. Likin1),
M. Liniers1),
D. López-Bruna1),
A. López-Fraguas1),
J. López-Rázola1),
A. López-Sánchez1),
E. de la Luna1),
A. Malaquias6),
F. Martín1),
R. Martín1),
M. Medrano1),
A.V. Melnikov3),
P. Méndez1),
K.J. McCarthy1),
F. Medina1),
B.Ph. van Milligen1),
I.S. Nedzelskiy6),
M.A. Ochando1),
P. Ortiz1),
L. Pacios1),
I. Pastor1),
M.A. Pedrosa1),
A. de la Peña1),
A. Petrov4),
S. Petrov7),
A. Portas1),
J. Romero1),
M.C. Rodríguez1),
L. Rodríguez-Rodrigo1),
A. Salas1),
E. Sánchez1),
J. Sánchez1),
K. Sarksian4),
S. Schchepetov4),
N. Skvortsova4),
F. Tabarés1),
D. Tafalla1),
V. Tribaldos1),
C.F.A. Varandas6),
J. Vega1),
B. Zurro1)
1) Laboratorio Nacional de Fusión. Asociación EURATOM-CIEMAT, Madrid, Spain
2) Institute of Plasma Physics, NSC KIPT, Kharkov, Ukraine
3) Institute of Nuclear Fusion, RNC Kurchatov Institute, Moscow, Russia
4) General Physics Institute, Russian Academy of Sciences, Moscow, Russia
5) Universitat Politècnica de Catalunya, Barcelona, Spain
6) Associação EURATOM/IST, Centro de Fusão Nuclear, Lisboa, Portugal
7) A.F. Ioffe Physical-Technical Institute, St.Petersburg, Russia
Abstract. This paper presents an overview of the experimental results and
progress in the investigation of the role of the magnetic configuration on
stability and transport in the TJ-II stellarator. The level of edge
fluctuations shows a significant increase when magnetic well is reduced.
However, although the magnetic well is the main stabilizing mechanism in
TJ-II, confinement is not dramatically affected when magnetic well is
reduced. MHD instabilities coupled together to ELM-like transport events
have been observed. The appearance of ELM-like transport events requires the
presence of a low order resonance in the confinement region. The propagation
of cold pulses is not in accordance with diffusive mechanisms. A dynamical
interplay between MHD instabilities and transport might explain not
diffusive transports mechanisms. TJ-II global energy confinement time and
plasma parameter dependencies are consistent with ISS95 predictions.
Spontaneous transitions to improved confinement regimes have been already
observed. A transient behaviour has been found in the plasma core with fast
drops in the electron temperature. Plasma potential measurements show
evidence of positive radial electric fields.
IAEA 2003
