Confinement transitions in TJ-II under Li-coated wall conditions

Confinement transitions in TJ-II under Li-coated wall conditions,10.1088/0029-5515/49/10/104018,Nuclear Fusion,J. Sánchez,M. Acedo,A. Alonso,J. Alonso

Confinement transitions in TJ-II under Li-coated wall conditions   (Citations: 5)
BibTex | RIS | RefWorks Download
J. Sánchez, M. Acedo, A. Alonso, J. Alonso, P. Alvarez, E. Ascasíbar, A. Baciero, R. Balbín, L. Barrera, E. Blanco, J. Botija, A. de Bustos
This paper presents the latest results on confinement studies in the TJ-II stellarator. The inherently strong plasma-wall interaction of TJ-II has been successfully reduced after lithium coating by vacuum evaporation. Besides H retention and low Z, Li was chosen because there exists a reactor-oriented interest in this element, thus giving special relevance to the investigation of its properties. The Li-coating has led to important changes in plasma performance. Particularly, the effective density limit in NBI plasmas has been extended reaching central values of 8 × 1019 m-3 and Te ≈ 250-300 eV, with peaked density, rather flat Te profiles and higher ion temperatures. Due to the achieved density control, a second type of transition has been added to the low density ones previously observed in ECRH plasmas: higher density transitions characterized by the fall in Halpha emission, the onset of steep density gradient and the reduction in the turbulence; which are characteristics of transition to the H mode. Confinement studies in ECH plasmas indicate that lowest order magnetic resonances, even in a low shear environment, locally reduce the effective electron heat diffusivities, while Alfven eigenmodes destabilized in NBI plasmas can influence fast ion confinement.
Journal: Nuclear Fusion - NUCL FUSION , vol. 49, no. 10, 2009
Cumulative Annual
View Publication
The following links allow you to view full publications. These links are maintained by other sources not affiliated with Microsoft Academic Search.
    • ...TJ-II is an experimental magnetic confinement fusion device [12] constructed in a heliac configuration at the Asociacion EURATOM-Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMA T) in Madrid, Spain...
    • ...At present, each NBI provides up to 450 kW of additional heating (tNBI ::; 100 ms) and, as a result, plasmas with ne(O) ::; 5 x 1019 m-3 have been attained with a lithium coating on the vacuum vessel wall [12]...

    S. K. Combset al. A new four-barrel pellet injection system for the TJ-II stellarator

Sort by: