1. France Japan Particle Physics laboratory (FJPPL) first workshop at KEK, Tsukuba, Japan 10 th May 2007 A_R&D_3 R&D on High Power Couplers for the ILC Hassen JENHANI (LAL/IN2P3/CNRS)

2. Frequency: 1,3 GHz Pulse length: 1,38 ms Pulse rate: 10 Hz Instantaneous power: 120 kW Coupling: Q ext = 4,6 10 6 (10 6 - 10 7 ) TTF-III coupler for the XFEL accelerator 30 TTF-III couplers were already fully conditioned at LAL (Fully automated conditioning procedure) TTF-III is also the baseline coupler for the ILC Warm part Cold part Ceramic windows Waveguide transition Inner conductor Operating characteristics of TTF-III in the XFEL accelerator:

3. Well defined conditioning procedure Controls synoptic 20µs..400µs (1 MW); 800µs & 1300µs (0.5 MW) Power coupler conditioning at room temperature TTF-III coupler pair during conditioning

4. Last conditioning time performances Need more tests Average ~ 21 h Parameter optimization Drastic conditioning time decrease after the conditioning parameters optimization: From 60 h in average to 21 h

5. Thanks to W.D Moeller & D. Kostin Conditioning validation Couplers don’t cause any limitation to the cavities. Tests done by DESY 35 MV/m

6. LAL prototypes: TTFV & TW60 Coupler prototype TTF-V Insulation using dielectric ring and insulating screws Capacitor (kapton) Coupler prototype TW60 TW60 TTF-V

7. Input coupler for STF baseline cavities at KEK TRISTAN Type Coaxial Disk Ceramic ; Warm Windows Cold Windows Warm Parts Cold Parts Coupling Waveguides Doorknobs

8. KEK high power tests: diagnostics 5MW Klystron Dummy Load PfPf PrPr PfPf PrPr Arc Sensor 3 Electron Probes 3 Electron Probes Monitor Camera Monitor Camera Vacuum Gauge (Cold side) Vacuum Gauge (Warm side) RF Power Meter Temperature Sensor

9. Total RF Processing Time up to 1.0 MW, 1.5 msec 1.0 MW, 1.5 ms, 5 Hz ~ 50 hrs. Very Careful Conditioning !! Processing time

10. 2006, Nov. : Assembly of one cavity Installation of one cavity into a cryomodule 2007: May : First cool-down test June: Installation of a warm coupler July: Second cool-down test August: disassemble 2008 Jan : First cool-down of 4 cavities Coupler & cavity horizontal test

11. Collaboration (1) Visit of LAL staff to KEK (December 2006): (H. Jenhani)  Participation to conditioning of the input power coupler for the STF baseline cavity  Visit of the KEK facilities (Conditioning test stand for input couplers, clean rooms, cryogenic facilities…)  Detailed presentation of the preparation and conditioning of Input power couplers at LAL. Many subjects were discussed: - Cleaning procedure - Couplers conditioning procedure - Diagnostics and observed signals - Multipacting - Storage procedure  Discussion about different design aspects of couplers and some of troubles associated to problems of some coupler manufacturing

12. Visit of KEK staff to LAL (February 2007) : (H. Hayano, S. Noguchi & E. Kako)  Presentation of the KEK last results and schedules concerning the input power couplers for the STF baseline cavity.  Discussions about the way to recover the manufacturing problems which were observed at the reception of the LAL couplers prototypes  Visit of the LAL facilities (Conditioning test stand for couplers, clean room & the coupler control and storage room) Both KEK and LAL coupler groups were very satisfied by the this collaboration and approved the maintain of this kind of involvement in all coupler activity aspects Potential collaboration perspective were jointly planned by KEK and LAL teams Collaboration (2)

13. Budget spending accounting LAL spending accounts: The total budget received in 2006: 6,000 € Visit to KEK (from 30 th November 2006 to 16 th December 2006): 4,440 € Visit to KEK (from 7 th May 2007 to 14 th May 2007): 1,560 € KEK spending accounts: Allocated Budget (for travel): 1,200kyen Visit of three KEK people to Orsay (from Feb 27 to Mar 07,2007): 1,000kyen

14. Conditioning experience: Optimization of conditioning parameters and coupler preparation procedure : A new series of TTF-III couplers will start to be conditioned at LAL soon. KEK staff can participate to some of these tests. Better understanding of coupler behavior by comparison of the LAL and KEK experiments results Conditioning of the LAL prototypes in the near future. Both of LAL & KEK teams can participate to data analysis and interpretation. Coupler prototypes: Exchange of some of design ideas (design simplification & diagnostic integration …) Technological solutions (materials, gaskets, how to cure defaults caused by some manufacturing problems…) KEK and LAL coupler teams collaboration perspectives (1)

15. TiN sputtering system for couplers ceramic windows was ordered by LAL (Reception in July 2007) KEK Know-how of the thin TiN layers deposition and characterization can provide a significant help to this activity Thin layers TiN deposition: Cryogenics : KEK long experience in the cryogenic field can help LAL coupler group to have better consideration of the cryogenic issues to upgrade coupler prototype designs. KEK and LAL coupler teams collaboration perspectives (2)

16. AIL Project 2007: Collaboration teams LAL coupler team: Dr. Alessandro Variola (Leader) Dr. Hassen Jenhani Dr. Pierre Lepercq Eng. Sophie Cavalier Eng. Mickael Lacroix KEK coupler team: Dr. Eiji Kako (Leader) Dr. Hitoshi Hayano Prof. Shuichi Noguchi Budget request for 2007 AIL budget application