Recent Electron Cyclotron Emission Results on TCV

Electron cyclotron emission (ECE) diagnostics on Tokamak à Configuration Variable (TCV) allow study of the electron temperature evolution in time with good spatial and temporal resolution at the high field side and low field side at various lines of sight. That is why ECE is being widely used to obtain both qualitative and quantitative information on heat transport, magnetohydrodynamics (MHD) phenomena, and fast electron dynamics. In this paper, a new regime on TCV with regular oscillations of the electron temperature in electron cyclotron current drive (ECCD) driven fully noninductive discharges and in discharges with a combination of ohmic/ECCD driven current is discussed. These oscillations are reminiscent of the oscillations of the central electron temperature (O-regime) seen on Tore Supra in fully noninductive lower hybrid current drive plasmas. A link between evolutions of the electron temperature, the MHD modes, and the current density profile on TCV is considered. In order to yield information on the properties of microturbulence of electrostatic and magnetic origin on TCV, a correlation ECE radiometer is currently under development. A technical description of the diagnostic is presented in this paper.

[1]  Stefano Coda,et al.  High field side measurements of non-thermal electron cyclotron emission on TCV plasmas with ECH and ECCD , 2002 .

[2]  F. C. Schüller,et al.  Evidence for high-m secondary islands induced by large low-m islands in a tokamak plasma. , 2005, Physical review letters.

[3]  LETTER TO THE EDITOR: Studies of high frequency hot ion instabilities by means of correlation ECE on Tore Supra , 2006 .

[4]  F. Imbeaux,et al.  New tokamak plasma regime with stationary temperature oscillations. , 2003, Physical review letters.

[5]  O. Sauter,et al.  Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime , 1999 .

[6]  Ambrogio Fasoli,et al.  Electron cyclotron emission spectrometry on the Tokamak a Configuration Variable , 2005 .

[7]  V. S. Udintsev,et al.  First Measurements of Oblique ECE with a Real-Time Movable Line of Sight on TCV , 2006 .

[8]  V. S. Udintsev,et al.  First Results of Correlation Electron Cyclotron Emission on Tore Supra , 2006 .

[9]  A. Wootton,et al.  Effects of limited spatial resolution on fluctuation measurements (invited) , 1995 .

[10]  O Sauter,et al.  From current-driven to neoclassically driven tearing modes. , 2002, Physical review letters.

[11]  Calvin Domier,et al.  Plasma transport properties in the presence of MHD modes studied by ECE at TEXTORThis is an extended , 2003 .

[12]  Olivier Sauter,et al.  Towards q-profile reconstruction through fast-MHD analysis on TCV , 2006 .

[13]  Paul H. Rutherford,et al.  Nonlinear growth of the tearing mode , 1973 .

[14]  M. Hirsch,et al.  Temperature fluctuation measurements with ECE on W7-AS , 1996 .

[15]  O. Sauter,et al.  Erratum: “Neoclassical conductivity and bootstrap current formulas for general axisymmetric equilibria and arbitrary collisionality regime” [Phys. Plasmas 6, 2834 (1999)] , 2002 .

[16]  J. B. Lister,et al.  Safety factor profile requirements for electron ITB formation in TCV , 2005 .

[17]  M. Kwon,et al.  Core temperature fluctuations and related heat transport in the Texas Experimental Tokamak-Upgrade , 1995 .

[18]  Hartfuss,et al.  Experimental evidence for electron temperature fluctuations in the core plasma of the W7-AS stellarator. , 1994, Physical review letters.

[19]  Conditions for anomalous energy and momentum transfer from electrons to ions in ECCD discharges on TCV , 2006 .

[20]  C. Watts,et al.  Upper limit on turbulent electron temperature fluctuations in the core of Alcator C-Mod , 2004 .

[21]  O. Sauter,et al.  Oscillations of Electron Temperature and Their Interplay with MHD in the Presence of Internal Transport Barriers on TCV , 2006 .

[22]  J. W. Oosterbeek,et al.  New ECE diagnostics for the TEXTOR-94 tokamak , 2001 .