1. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 1/ 25 1 Tore Supra : Physics, Technology… and Strategy André Grosman Institut de Recherches sur la fusion par confinement magnétique (CEA/DSM/IRFM)

2. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 2/ 25 2 OUTLINE  What is Tore Supra?  What I (and many others) learnt from R. Aymar (working) proximity?  R. Aymar’s legacy

3. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 3/ 25 3 Gross energy production is the aim… what is the way (lat. ITER)? A 40 years effort to establish the basis of fusion science The path to full scientific and technical integration remains very much challenging

4. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 4/ 25 4 Fusion energy production needs a systemic approach… Paving the way(s) can be successful only if the directions are correct R&D Partial integration (ex. : Diagnostics) Partial integration (ex. : Plasma facing components) Partial integration (ex. : Heating) Full integration (including e.g. RAMI, Nuclear, Operation…)

5. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 5/ 25 5 … and a systemic approach requires a strategy Strategy requirements should be at their highest as the problem to be solved is essential for the whole mankind: >necessitates a very long term vision >requires a strong and sometimes long elaboration >validation will stem from its evolution capability

6. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 6/ 25 6 Tore Supra, a strategic breakthrough In the late 70s, energy supply was very high on political agenda, a unique opportunity to make a step forward in fusion energy research, based on tokamaks promising results. Major Proposals: >JET, a thermonuclear device (Q~1) >Devices dedicated to solving the Plasma wall interactions issues (ASDEX : divertor, …) >A missing link? A long discharge tokamak…

7. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 7/ 25 7 Completing the strategy… 10 100 100010000 1000 100 10 1 1000 100 10 Discharge duration (s) Power kW th MW th reactor Long duration plasmas … Tore Supra Thermonuclear plasma + robotics, tritium technology … JET ITER ITER = INTEGRATION Reactor Materials + T breeding blanket 1

8. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 8/ 25 8 a strong step forward in integrating physical + technological knowledge a strong step forward in integrating physical + technological knowledge feasibility of a fusion reactor  feasibility of a fusion reactor Long discharge, what does it mean? MHD 10 -3 10 -2 10 10 0 1 2 3 4 5 6 Energy confinement ELM’s - Disruption Cooling of P.F.C. Current diffusion Total thermalization second Plasma Energy Particles Particle confinement Wall inventory PFC lifetime JET, ASDEX, … Tore Supra (1981 project) and …capability Mastering Fusion reactor

9. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 9/ 25 9 Long discharge, what does it implies ? Long pulses required to : –develop & test technologies in realistic conditions –extend fusion performances on relevant duration, and address long time scale physics issues –evaluate the long term impact of weak phenomena, not revealed on shorter pulses –Develop real time control techniques (integrated operation)

10. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 10/ 25 10 control the discharge sustain the magnetic configuration inject and exhaust the power fuel and pump the discharge LONG PULSE HEATING SYSTEMS COOLED PFCs + ACTIVE PUMPING Long discharges : How to achieve them? [courtesy of D. Van Houtte]SUPERCONDUCTINGCOILS NON INDUCTIVE CURRENT DRIVE (except stellarators/heliotrons) LONG PULSE FUELLING SYSTEMS REAL TIME CONTROL (long pulse diags)

11. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 11/ 25 11 Major Radius 2.40 m Minor Radius 0.72 m Plasma Volume 25 m 3 Magnetic Field 4 T NbTi in a superfluid He bath at 1.8 K, Plasma Current 1.5 MA Fuelling methods: classical, pulsed supersonic and pellets Heating RF Waves (LHCD:8MW, ICRH:12MW, ECRH:2MW) … Only one tokamak with - un superconducting toroïdal magnet, - RF heating and current drive, - actively cooled plasma facing components. TORE SUPRA, a unique facility 200 C° pressurized (40 bar) water actively cooled Plasma Facing Components

12. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 12/ 25 12 Plasma facing components integration

13. 13 Tore Supra PFCs learning curve

14. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 14/ 25 14 Test Facility FE 200 electron gun : 200kW Industrial development and qualification, a key to success

15. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 15/ 25 15 TORE SUPRA 2002 CIEL CONFIGURATION WITHSTANDS 10 MW/m²

16. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 16/ 25 16 Moving to Cadarache, another strategic issue Before 1986 Fontenay-aux-Roses (TFR tokamak) Grenoble (Petula tokamak and Wega stellerator) 1984 - 1986 : Bringing together two teams and building another one (40% newcomers) About a challenge : Tore Supra Prospects a site for the next (nuclear) step April 1988: first Tore Supra plasmas (decision to build: 1981) >Strong confidence (costs, schedule, performance) >Strong thrust for teams

17. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 17/ 25 17

18. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 18/ 25 18 Site operations (larger scale!) Sources : Agence ITER France and ITER Organisation

19. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 19/ 25 19 Tore Supra achievement (2004) : 6 minutes, 1GJ (~ 10 28 eV) Time (s) Plasma density Current drive power Plasma Current 3MW

20. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 20/ 25 20 A recipe to become Robert Aymar

21. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 21/ 25 21 Methodology Think global, act local!!! In 1968, he proposed a revolution … about laboratory organisation … Sticked to it … Implemented it (Tore Supra project) >Convincing his collaborators

22. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 22/ 25 22 Intellectual integrity No a priori on proposals (good or bad) Proposals deserve … >First to be analysed >Then improved and developed … or discarded. Proposals should be integrated

23. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 23/ 25 23 Personal commitment + Respect Example : Tore Supra coil damage (1988) In a nutshell… Analyse Find a technical solution Minimise undesirable consequences Mobilise teams … Give value to others’ efforts, ideas Share responsibilities

24. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 24/ 25 24 Conclusions R. Aymar’s legacy about Tore Supra is still a treasury : The strategic lines proved to be right The implementation allowed to reach major steps The device capability large enough to allow and promote « upgrades » His long range influence on the CEA Fusion institute is still valid. It was an esential link in paving the way to ITER

25. Robert Aymar’s 75th birthday celebration colloquium at CERN A. Grosman 25/ 25 25 Tore Supra team around the machine Everybody tells him : Merci!