R. Cavazzana – RFX-mod programme Workshop – 21 - I Experimental Proposals Submitted to TF4 Roberto Cavazzana ● TF4 Topics ● Urtext edition of proposals ● What's left From wikipedia: an urtext edition of a work of classical music is a printed version intended to reproduce the original intention of the composer as exactly as possible.

R. Cavazzana – RFX-mod programme Workshop – 21 - I Some remarks… The quality of proposals is considerably improved since last year. ● Experience gained by many people, including the young, by participating in the experiments and sharing the results. -> Contain new ideas. -> Well constructed. -> More focused. Report from Accounting Dept.: 39 proposals 161 gross total exp days 102 net total exp days

R. Cavazzana – RFX-mod programme Workshop – 21 - I Topic List TF Optimization of RFX-mod discharges: RFP, tokamak and non standard plasmas ● Start-up scenarios ● Equilibrium control, in particular in view of high current operation ● Feedback on global quantities (Toroidal field, current) ● Magnetic configuration symmetry ● Development of tokamak and low-q scenarios ● Effect of plasma shaping (X-point,...) ● Development of reference discharges TF5 2008: Density Control and Plasma-Wall Interaction ● Effect of wall conditioning techniques ● Optimization of existing wall conditioning techniques ● Development of new techniques ● Characterization of wall conditions and of fuel inventory ● Improvement and standardization of fueling techniques ● Assessment of heat loads and of the effect of pWI on plasma performance (density control)

R. Cavazzana – RFX-mod programme Workshop – 21 - I TF4 Topic List Reformulated Magnetic Optimization ● Start-up scenarios and Reference discharges ● Equilibrium control - Feedback on global quantities (toroidal field, plasma current) - Horizontal Equilibrium and plasma shaping (X-point,...) ● Error field reduction and Symmetry improvement ● Development of tokamak, low-q and non-standard cfgs ● Test of Diagnostic Systems Density control ● Optimization and development of wall conditioning techniques ● Characterization of wall conditions and fuel inventory ● Improvement and standardization of fueling techniques ● Heat loads and effects of Plasma Wall Interaction on performance

R. Cavazzana – RFX-mod programme Workshop – 21 - I Test of Diagnostic Systems TF Exp N.1234 Days ProposersTitle 7 x1F.Bonomo, M.Valisa DNBI: neutral beam current observation 8 x2F.Bonomo, M.Valisa, F.Milani, L.Zanotto DNBI: feasibility tests for CX and Stark measurements 18 x1F.Bonomo, M.Valisa DNBI operation with a modified scrape-off layer 12 xx2 Carraro,Alfier,Fassina,Menmuir,Pasqualot to,Puiatti,Valisa Optimisation of metals Laser Blow Off injection in RFX-mod

R. Cavazzana – RFX-mod programme Workshop – 21 - I Non RFP Configurations TF Exp N.1234 Days ProposersTitle 14 xx5 Spizzo, Puiatti, Valisa, Scarin, Cappello, Piovan, Zanotto, Zuin, Vianello, Alfier, Auriemma High density ULq plasmas 75 x x4 Matteo Zuin, N. Vianello, R. Piovan, R. Cavazzana, D. Bonfiglio, L. Zanotto Edge probe measurements in ULQ discharges TF Exp N.1234 Days ProposersTitle 72 x2M.Zuin Alternating Gradient Quadrupolar Focusing 76 x x2M. Zuin, N. Vianello Bumpy RFP TF Exp N.1234 Days ProposersTitle 63 xx4 N.Vianello, R. Cavazzana, E. Martines, M. Zuin, B. Momo, G. Marchiori ESN-DN Tokamak discharges 102 xx4 Puiatti,Valisa, Spizzo, Scarin, Carraro, Cavazzana Tokamak discharges near the Greenwald limit

R. Cavazzana – RFX-mod programme Workshop – 21 - I Reference Discharges I – High Current TF Exp N.1234 Days ProposersTitle 108 x x4 P. Piovesan, G. Marchiori, L. Marrelli, L. Piron, A. Soppelsa, P. Zanca Optimization of the CMC scheme in preparation of 2MA operation 52 x x12 R.Cavazzana, R.Lorenzini, F.Milani, G.Marchiori, G.Spizzo, D.Terranova, N.Vianello and interested people. The 1.8 and 2 MA discharges 73 xx x4 Matteo Zuin, Paolo Piovesan, Rita Lorenzini, Roberto Cavazzana QSH study through F scan at high current 81 x x4 R.Cavazzana, M.Zuin, E.Martines, B.Momo and interested people. QSH and SHAx at High Density 82 x x4 R.Cavazzana, M.Zuin, M.Spoloare, E. Martines, B.Momo, Extreme F ~ 0- RFP

R. Cavazzana – RFX-mod programme Workshop – 21 - I Reference Discharges II - Other TF Exp N.1234 Days ProposersTitle 20 x8 T. Bolzonella, L. Grando, P. Innocente, F. Milani, L. Novello, S. Ortolani, S. Peruzzo, R. Piovan Slow plasma current rise 65 xx4 N.Vianello, R. Cavazzana, E.Martines, M.Spolaore, M.Zuin, G. De Masi, S. Spagnolo, B. Momo Low current high density discharge 121 xxx8 B. Chapman, P. Franz, D. Terranova, M. Valisa Production of low-current, low- density standard plasmas in H2, D2, and He as targets for application of PPCD 55 xxxx12M. Spolaore, P. Franz, P. Zanca, Plasma current parameter scaling on CMC discharges

R. Cavazzana – RFX-mod programme Workshop – 21 - I Equilibrium Control TF Exp N.1234 Days ProposersTitle 99 x12 R.Cavazzana, G.Marchiori, A.Soppelsa, L.Grando, L.Zanotto, L.Novello, E.Gaio, … Optimization of the Horizontal Equilibrium 98 x3 P.Bettini, R. Cavazzana, G. Marchiori, A.Soppelsa, T. Bolzonella, … Development of a Flat Top Plasma Current Controller 9 x2L. Zanotto and all interested people Operation with toroidal power supply in open-loop control 101 x4 R.Cavazzana, G.Marchiori, L.Zanotto, A.Salata, A.Soppelsa, … Precise F controller

R. Cavazzana – RFX-mod programme Workshop – 21 - I Error Field Correction and Symmetry TF Exp N.1234 Days ProposersTitle 67 x x4M. Zuin, G. Marchiori, R. Cavazzana High order m=0 mode control 71 x x4 M. Zuin, G. Marchiori, R. Cavazzana, L. Zanotto Low order m=0 mode control 125 x8 A. Soppelsa, L. Marrelli, P. Piovesan, D.Terranova Full mutual couplings scan 84 x x4 L.Grando, G.Marchiori, L.Marrelli, P.Piovesan, L.Piron, A.Soppelsa, D.Terranova Field Error Correction

R. Cavazzana – RFX-mod programme Workshop – 21 - I Start-up TF Exp N.1234 Days ProposersTitle 89 x4T. Bolzonella, P. Innocente, S. Dal Bello Plasma startup at low Vloop 100 x2R Cavazzana, A. Canton, S. Dal Bello,... Lean Startup

R. Cavazzana – RFX-mod programme Workshop – 21 - I Density Control TF Exp N.1234 Days ProposersTitle 4 xx Gazza, Canton, Carraro, Puiatti, Valisa, Scarin, Agostini, Innocente, Menmuir, Zaniol Spectroscopic characterization of the wall and plasma boundary 36 x4 P. Innocente, D. Terranova, A. Canton, F. Auriemma, S. Dal Bello and FC Group Lithium Pellets for First Wall Conditioning 48 x12 Alfier, Mazzitelli, Scarin, Dal Bello, Cavazzana, Canton, Innocente, Spolaore, … First Wall Conditioning by means of Li-CPS limiter 129 x6S. Dal Bello, A. Canton, R. Cavazzana Optimization of Baking and Boronisation procedures 130 x2A. Canton, S. Dal Bello, R. Cavazzana Optimization of Glow Discharge Cleaning and Preloading 131 x3A. Canton, S.Dal Bello, E. Gazza, R.Cavazzana Helium discharges and Hydrogen de- saturation 132 x S. Dal Bello, A. Canton, M. Spolaore, P.Innocente,.. Test on samples inserted during RFX plasma discharges 133 x E. Vassallo et al. (IFP-Milano), S Dal Bello, A. Canton, P. Innocente, M.Spolaore, … “Scavenging” effect studies – samples insertion 134 x S. Dal Bello, A. Alfier, A. Canton., R. Cavazzana, P. Innocente, M.Spolaore … Test on samples inserted during RFX GDC-wall conditioning

R. Cavazzana – RFX-mod programme Workshop – 21 - I A personal priority list … ● Horizontal Equilibrium control (thin shell + meachanical structure) with gaps (  eff ~70ms) conducting vessel out of equilibrium single quadrant power supply critical for tokamak an low q operation too!! ● Field error correction – Shape - Reduction of localized plasma wall interaction. Strategies: active correction windings current balancing smooth and cautious waveform programming ● MHD Equilibrium control Widens and makes safer the operating range ● Effective Field Mapping of Br system (pseudo-decoupler) - An essential tool (even if not in real time)

R. Cavazzana – RFX-mod programme Workshop – 21 - I … ● Control of density and impurities - Machine Operation reduce the need of GDC more useful shots. - Plasma performance reduction of impurities –field error reduction –equilibrium –wall treatments Methods - Characterization the Glow Discharge cleaning and pre-loading. - Start-up optimization (breakdown and reversal) - Field error reduction - Toroidal field symmetrization & m=0 structure modification Challenging and time consuming, but pays …

R. Cavazzana – RFX-mod programme Workshop – 21 - I What's left ? A more general "real-time" trigger (pellets, DRE sync, …) Prop. 49/TF3 /Alfier, Manduchi / Thomson scattering systems synchronization on QSH events. A current controller for tokamak operation these may drastically reduce the need of experimental time and provide much clear results. ?

R. Cavazzana – RFX-mod programme Workshop – 21 - I Toroidal System ● 12 independent sectors ● full four quadrant power supply dedicated for each sector - 3 kV 6 kA (18 MVA) f pwm ~ 1400 Hz Up to now its capability had been very partially exploited!!