Confinement Transitions in TJ-II under Li-coated Wall Conditions Articles uri icon

authors

  • SÁNCHEZ, J.
  • ACEDO, M.
  • ALONSO, A.
  • ALONSO, J.
  • ALVAREZ, P.
  • ASCASIBAR, E.
  • BACIERO, A.
  • BALBIN, R.
  • BARRERA, L.
  • BLANCO, E.
  • BOTIJA, J.
  • DE BUSTOS, A.
  • DE LA CAL, E.
  • CALVO, I.
  • CAPPA, A.
  • CARMONA, J. M.
  • CARRALERO, D.
  • CARRASCO, R.
  • CARRERAS, B.A.
  • CASTEJON, F.
  • CASTR0, R.
  • CATALAN, G.
  • CHMYGA, A. A.
  • CHAMORRO, M.
  • ELISEEV, L.
  • ESTEBAN, L.
  • ESTRADA, T.
  • FERNANDEZ, A.
  • FERNANDEZ GAVILAN, R.
  • FERREIRA, J. A.
  • FONTDECABA, J. M.
  • FUENTES, C.
  • GARCIA GONZALO, LUIS
  • GARCIA CORTES, MARIA ISABEL
  • GARCIA GOMEZ, R.
  • GARCIA REGANA, J. M.
  • GUASP, J.
  • GUIMARAIS, L.
  • HAPPEL, T.
  • HERNANZ, J.
  • HIDALGO, C.
  • JIMENEZ, J.A.
  • JIMENEZ DENCHE, A.
  • JIMENEZ GOMEZ, R.
  • JIMENEZ REY, D.
  • KIRPITCHEV, I.
  • KOMAROV, A. D.
  • KOZACHOK, A. S.
  • KRUPNIK, L.
  • LAPAYESE, F.
  • LINIERS, M.
  • LOPEZ BRUNA, DANIEL
  • LOPEZ FRAGUAS, A.
  • LOPEZ RAZOLA, J.
  • LOPEZ SANCHEZ, A.
  • LYSENKO, S.
  • MARCON, G.
  • MARTIN, F
  • MAURIN, V.
  • MCCARTHY, K. J.
  • MEDINA, F.
  • MEDRANO, M.
  • MELNIKOV, A. V.
  • MENDEZ, P.
  • VAN MILLIGEN, B.
  • MIRONES, E.
  • NEDZELSKIY, I. S.
  • OCHANDO, M.
  • OLIVARES, J.
  • DE PABLOS, J.L.
  • PACIOS, L.
  • PASTOR, I.
  • PEDROSA, M.A.
  • DE LA PENA, A.
  • PEREIRA, A.
  • PEREZ, G.
  • PEREZ RISCO, D.
  • PETROV, A.
  • PETROV, S.
  • PORTAS, A.
  • PRETTY, D.
  • RAPISARDA, D.
  • RATTA, G.
  • REYNOLDS, J. M.
  • RINCON, E.
  • RIOS, L.
  • RODRÍGUEZ, C
  • ROMERO, J. A.
  • ROS, A.
  • SALAS, A.
  • SÁNCHEZ, M.
  • SÁNCHEZ, E.
  • SANCHEZ SARABIA, E.
  • SARKSIAN, K.
  • SEBASTIAN, J. A.
  • SILVA, C.
  • SCHCHEPETOV, S.
  • SKVORTSOVA, N
  • SOLANO, E. R.
  • SOLETO, A.
  • TABARES, F.
  • TAFALLA, D.
  • TARANCON, A.
  • TASCHEV, YU.
  • TERA, J.
  • TOLKACHEV, A.
  • TRIBALDOS, V
  • VARGAS, V. I.
  • VEGA, J.
  • VELASCO, G.
  • VELASCO, J. L.
  • WEBER, M.
  • WOLFERS, G.
  • ZURRO, B.

publication date

  • October 2009

issue

  • 10

volume

  • 49

International Standard Serial Number (ISSN)

  • 0029-5515

Electronic International Standard Serial Number (EISSN)

  • 1741-4326

abstract

  • 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 Halfa 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.