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(EXP4/09) Heating, Current Drive and MHD Control Using ECH in TCV

T. Goodman¹⁾, TCV Team
 
¹⁾ CRPP/EPFL, Lausanne, Switzerland

Abstract.  The 6 beam 2nd harmonic X-mode (X2), 3MW, ECH/ECCD system of the TCV tokamak allows a fine tailoring of the deposition profiles in the plasma. The sensitivity of the sawtooth period to the deposition location is used to increase the equilibria reconstruction and ray-tracing accuracy. Off-axis ECH, followed by on-axis counter-ECCD produces improved central confinement regimes in which $\tau_{\mathrm{Ee}}^{}$ exceeds RLW scaling by a factor of 3.5. The PRETOR transport code (incorporating an RLW local transport model but constrained by the experimental density profiles) predicts an extreme sensitivity of $\tau_{\mathrm{Ee}}^{}$ to the deposition location of the counter-ECCD. This is confirmed by experiments. Sawtooth simulations using PRETOR, including the effects of current drive with inputs from the TORAY ray-tracing code, are in good agreement with experimental results. These results are an initial benchmark for the package of analysis codes, LIUQE / TORAY / PRETOR used during ECH/ECCD experiments on TCV.

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