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IOS-1.2 Study seeding effects on ITER demo discharges ( Oct 2011). - closely related to IOS-1.1, development of ITER demonstration discharges. Contributors: A. Kallenbach (Spokes person, AUG), T. Petrie (DIII-D), G. Maddison (JET),
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IOS-1.2 Study seedingeffects on ITER demodischarges (Oct 2011) - closely related to IOS-1.1, development of ITER demonstration discharges Contributors: A. Kallenbach (Spokes person, AUG), T. Petrie (DIII-D), G. Maddison (JET), M. Reinke/S. Wolfe (C-Mod), V. Soukhanovskii (NSTX) Strategy: Ideally, ITER demonstration discharges should be developed with integrated impurity seeding. Due to technical constraints and difficulties, seeded scenarios and ITER demonstration discharges (IOS-1.1) are developed in parallel, to be combined in the future. The combination of low q95, and high is in particular challenging for high-Z devices. Sufficient central heating and ELM control are essential. Physics Studies: Multi-machine similarity discharges with identity params *, n/nGreen and P/R (2010 /2011) B=const, Ip~R, validate radiative efficiency data and scalings dZeff in ITER Combine radiative seeding with ELM control (RMPs, pellets, …) Status/plans: Seeding results (AUG, JET, C-mod, DIII-D) reported on PSI 2010 (JNM online/in press) Wait for new seeding results from JET with ILW, then close IOS-1.2 (possibly define follow-up JE) Final report foreseen for autumn 2012 Focus of experiments and analysis in remaining time: 1) seeding in ITER-shaped plasmas (JET, C-Mod, AUG) 2) identify the best sensor signal for feedback control in ITER Arne Kallenbach
ASDEX Upgrade: High power seedingwithpeakheatload < 5 MW/m2 Peak load < 5 MW/m2 ! Combined strong D divertor puff, feedback controlled N divertor seeding (q95=3.7, u=0.1, l=0.43) Modelling with B2-Eirene about to start Arne Kallenbach
OSP sweeping + RTC seeding in JET Type I H-mode Optimum sensor for heatflux feedback control not yet clear JET uses NV emission line (20.93 nm) so far References from feedforwardN series v. inter-ELM radiance of 20.93 nm line (NVA) showshot-to-shotlegacy (in all-Cmachine). (3 points with outward-shifted OSP removed) Unseeded pulses with OSP sweeping at 4 Hz show drop in outboard-target inter-ELM heat load (and Zefft). Adding N seeding under RTC (using inboard-divertor filtered NVA as sensor) reduces inter-ELM heat load further while maintaining H98yt & lower Zefftgreater effect per extrinsic ion. Similar inter-ELM exhaust moderation in swept, RTC case for only 40% of N input in unswept, feedforward counterpart. Arne Kallenbach