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Overview of TJ-II experiments |
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F. de Aragón, E. Ascasíbar, A. Baciero, R. Balbín, E. Blanco,
J. Botija, B. Brañas, E. Calder´on, A. Cappa, J.A. Carmona,
R. Carrasco, F. Castejón, J.R. Cepero, A.A. Chmyga,
J. Doncel, N.B. Dreval, S. Eguilior, L. Eliseer, T. Estrada,
J.A. Ferreira, A. Fernández, J.M. Fontdecaba, C. Fuentes,
A. Garcíıa, I. García-Cortés, B. Gonçalves, J. Guasp,
J. Herranz, A. Hidalgo, R. Jiménez, J.A. Jiménez,
D. Jiménez-Rey, I. Kirpitchev, S.M. Khrebtov, A.D. Komarov,
A.S. Kozachok, L. Krupnik, F. Lapayese, M. Liniers,
D. López-Bruna, A. López-Fraguas, J. López-Rázola,
A. López-Sánchez, E. de la Luna, G. Marcon, R. Martín,
K.J. McCarthy, F. Medina, M. Medrano, A.V. Melnikov,
P. M´endez, B. van Milligen, I.S. Nedzelskiy, M. Ochando,
O. Orozco, J.L. de Pablos, L. Pacios, I. Pastor, M.A. Pedrosa,
A. de la Peña, A. Pereira, A. Petrov, S. Petrov, A. Portas,
D. Rapisarda, L. Rodríguez-Rodrigo, E. Rodríguez-Solano,
J. Romero, A. Salas, E. Sánchez, J. Sánchez, M. Sánchez,
K. Sarksian, C. Silva, S. Schchepetov, N. Skvortsova,
F. Tabarés, D. Tafalla, A. Tolkachev,V. Tribaldos, I. Vargas,
J. Vega, G.Wolfers and B. Zurro
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2005 |
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DOI |
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Resumo |
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This paper presents an overview of experimental results and progress made in investigating the role of magnetic
configuration on stability and transport in the TJ-II stellarator. Global confinement studies have revealed a
positive dependence of energy confinement on the rotational transform and plasma density, together with different
parametric dependences for metallic and boronized wall conditions. Spontaneous and biasing-induced improved
confinement transitions, with some characteristics that resemble those of previously reported H-mode regimes
in other stellarator devices, have been observed. Also, magnetic configuration scan experiments have shown an
interplay between magnetic structure (rationals, magnetic shear), transport and electric fields. Although the dc radial
electric fields are comparable with those expected from neoclassical calculations, additional mechanisms based on
neoclassical/turbulent bifurcations and kinetic effects are needed to explain the impact of magnetic topology on
flows and radial electric fields. Hydrocarbon fuelling experiments in configurations with a low-order rationalvalue
in the rotational transform located in the proximity of the last closed flux surface (n = 4/m = 2) have shown the
impurity screening properties related to the expected divertor effect. The first TJ-II experiments in neutral beam
injection plasmas are reported. |
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