Bremond, S. P.

Paper	Title	Page
WEP098	Failure Mode And Recovery Strategies For The Operation Of The Tore Supra Tokamak	591
	P. Moreau, S. P. Bremond, J. Bucalossi, D. Douai, P. Hertout, F. Leroux, P. Pastor, N. Ravenel, F. Saint-Laurent Association EURATOM-CEA, St Paul Lez Durance M. Lennholm EFDA-JET, Abingdon, Oxon
	The operation of the Tore Supra tokamak requires the orchestration of more than 50 systems including several sub-plants (cryogenic plant, magnetic coils, water cooling loops, multi megawatt heating systems, etc.), as well as plasma diagnostics. To ensure both plasma performance and safe operation, it is crucial to optimise the way each plasma discharge is driven. The Tore Supra real time control system (RTCS) has been developed on that purpose. Default detections is performed at both sub-plant systems and inter-plant links levels using hardware and software means. Additionally, a dedicated unit is devoted to the supervision of the overall plasma discharge by collecting the sub-plant status and the plasma parameters from diagnostics. Any abnormal event or discrepancy with respect to reference parameters is detected and classified as machine protection event (e.g. electrical arcing on RF antenna or too high impurity level, etc.), or as plasma performance discrepancy event (e.g. degraded confinement regime). Then a pre-defined recovery strategy is applied (e.g. balance load distribution between sub-plants). Several examples of detection and recovery strategies will be reported.
	Poster
THP065	Plasma Position Control and Current Profile Reconstruction for Tokamaks	788
	F. Saint-Laurent, S. P. Bremond, P. Moreau Association EURATOM-CEA, St Paul Lez Durance J. Blum, C. Boulbe, B. Faugeras Université de Nice Sophia-Antipolis, Nice
	In the field of fusion reactor studies, the Tore Supra tokamak explores the way of high-power long-duration plasma discharges. When operating such discharges, the first wall, located inside the vacuum vessel in front of the plasma, must sustain the heat flux up to 10 MW/m2, released by the high temperature plasma following both convection and radiation processes. Real-time identification and control of the plasma boundary are thus mandatory to safely operate the device. The best way is to solve the 2D Grad-Shafranov equation which describes the axisymmetric plasma equilibrium and thus to identify the non-linear source of plasma current. The fast solver EQUINOX using finite element method and fixed-point algorithm was developed and implemented since 2003. Boundary conditions were imposed using external magnetic measurements only. For advanced plasma regimes (high confinement regime) the current profile must be controlled and thus real-time determined. As magnetics are no longer sufficient to constraint the solution, information provided by other diagnostics were included and tested as additional constraints. Some examples of the resulting current profile improvement will be given
	Poster