1. CLIC related CERN-KEK collaboration J.P.Delahaye for the CLIC study team

2. CERN-KEK Committee 07/12/07J.P.Delahaye2 Outline Long standing collaboration between CERN & KEK in the frame of Linear Colliders R&D CERN participation in KEK Accelerator test facility (ATF): –Generation of low emittance beams (micro rad-m) –Focusing to extremely low beam sizes (nm) KEK participation in High Gradient RF structures R&D (100 MV/m): –Fabrication of normal conducting structures@KEK –Tests with power of structures @ KEK

3. CERN Participation in ATF

4. CERN-KEK Committee 07/12/07J.P.Delahaye4 ATF collaboration  damping-ring prototype ATF at KEK achieves world’s smallest emittance beams; pioneered numerous diagnostics developments (laser wires, diffraction radiation, X-ray optics, interferometry, …) tuning & correction schemes trains young generation of accelerator physicists  final focus ATF-2 truly international project uses low-emittance beam extracted from ATF ring aims to produce 30 nm spot size with less than 5% orbit “jitter” test of diagnostics (nm-BPMs, spot-size monitors) test of feedbacks & stabilization schemes  polarized e+ source via Compton back-scattering (PosiPol collaboration; beam tests at ATF)

5. CERN-KEK Committee 07/12/07J.P.Delahaye5 E=1.28GeV Ne=1x10 10 e - /bunch 1 ~ 20 bunches Rep=1.5Hz X emit=2.5E-6  m ( at 0 intensity) Y emit=2.5E-8  m ( at 0 intensity) Accelerator Test Facility Damping ring Linac H. Hayano ATF is the largest LC Test Facility ~ ILC emittance requirements

6. CERN-KEK Committee 07/12/07J.P.Delahaye6 ATF demonstrated single bunch emittance  x ~3.5-4.3  m (1.4-1.7 nm)  y ~13-18 nm (5-7 pm) at 8x10 9 e - /bunch CLIC target values  x ~0.5  m  y ~3 nm at 4x10 9 e - /bunch ?

7. CERN-KEK Committee 07/12/07J.P.Delahaye7 Beam sizes at Collisions

8. CERN-KEK Committee 07/12/07J.P.Delahaye8 KEK Crab Cavity Group has relocated clearing space for ATF2. Floor refurbishment finished this fall. ATF2 requires rearranging extraction line components and connecting it to ATF2 beam line during 2008 summer shutdown.

9. CERN-KEK Committee 07/12/07J.P.Delahaye9 ATF/ATF2 master schedule consistent with CLIC feasibility study by 2010

10. CERN-KEK Committee 07/12/07J.P.Delahaye10 effective since August 1, 2005 ATF-MoU about 20 member institutes

11. CERN-KEK Committee 07/12/07J.P.Delahaye11

12. CERN-KEK Committee 07/12/07J.P.Delahaye12 ATF Spokesperson(s) J. Urakawa, KEK Three Deputies (with help of sub-Deputies from KEK) Deputy for Beam operation: S.Kuroda (T.Okugi) Deputy for Hardware maintenance: N.Terunuma (M.Kuriki) Deputy for ATF2: A.Seryi (T.Tauchi) ATF System and Group Coordinators (SGC) H.Weise, DESY F.Zimmermann, CERN Philip Burrows, UK Grahame Blair, UK P. Bambade, LAL M. Ross, FNAL J. Nelson, SLAC A. Seryi, SLAC R. Meller, Cornell (US Univ), J.Gao, IHEP/Beijing, E.S.Kim, KNU,/Korea K.Kubo,S.Kuroda,N.Terunuma,M.Kuriki,T.Tauchi,T.Okugi,R.Sugawara, KEK, T.Sanuki, University of Tokyo

13. CERN-KEK Committee 07/12/07J.P.Delahaye13 ATF Technical Board (TB) Europe…………………………... E. Elsen, DESY G. Blair, RHUL (Royal Holloway, University of London) P. Burrows, Oxford University+ QMUL F. Zimmermann, CERN A.Wolski, CI North America………………….. T. Raubenheimer, SLAC M. Ross, FNAL Asia……………………………… K. Yokoya, KEK N. Toge, KEK T. Sanuki, University of Tokyo J. Gao, IHEP E-S. Kim, KNU

14. CERN-KEK Committee 07/12/07J.P.Delahaye14 ATF International Collaboration Board (ICB) Bob KephartFNAL Brian Foster Oxford David MillerUCL Mitsuaki Nozaki KEK Michael Harrison BNL J.P. Delahaye CERN Jai Gao IHEP John CorlettLBNL Kaoru YokoyaKEK Eckhart ElsenDESY Nobaru SasaoKyoto University Paterson, Ewan (chair)SLAC Philip Burrows Oxford Robert MellerCornell University Sachio Komamiya University of Tokyo Tsutomu Nakanisi Nagoya University Washio Masakazu Waseda University Jinhyuk Choi PAL

15. CERN-KEK Committee 07/12/07J.P.Delahaye15 CERN hardware contribution to ATF-2 honeycomb table (from TMC) honeycomb structure with length 2.4 m, width 0.8 m, height 0.8 m absence of structural resonance below 230 Hz table previously used for CLIC stabilization study presently on loan at LAPP/Annecy ATF purpose: to stabilize the final quadrupoles stabilizing feet (STACIS2000 from TMC) equipped with geophones, rubber pads for passive damping, and piezo-electric movers for active damping of load vibrations induced from the ground had been offered too, but LAPP found: not useful for ATF2 value about 100,000 CHF (8.72 MYen) LAPP/Annecy will ship honeycomb table (or identical new table it will purchase) table to KEK in 2008

16. CERN-KEK Committee 07/12/07J.P.Delahaye16 CLIC test stand for vibration measurements & magnet stabilization studies S. Redaelli, R. Assmann

17. CERN-KEK Committee 07/12/07J.P.Delahaye17 ongoing & planned CERN ATF “studies” development of commissioning strategy; already wrote section of design report investigation of optimum beam-based alignment pro- cedures with pertinent specification of BPM ranges simulation of IP tuning and maximum tuning knob ranges survey of relevant collective effects in ATF-2 and ATF extraction line; particularly wake fields + ions participation in commissioning activities 1 person month 3 person months 4 person months 1 person month in total: 1 person year approved by CSC on 13.10.2005 EUROTeV& BDIR London Meeting 2005; Nanobeam’05

18. CERN-KEK Committee 07/12/07J.P.Delahaye18 CERN live participation many pre-2004 visits (J.-P. Potier, F. Zimmermann) 7 th Int’l ATF coll. mtg 2001 (H. Braun, F. Zimmermann) 3-wk ATF visit by M. Korostelev 12/2004 - measurements of ATF DR damping times with and w/o wiggler - alternative low-emittance DR design 3-wk ATF visit by R. Tomas 12/2006 - measurements of resonance driving terms in ATF damping ring - skew quadrupole requirements for vertical dispersion correction at ATF2 - feasibility study of octupole tail folding for ATF2 2-wk ATF visit by R. Tomas 12/2007 1-wk ATF visit by F. Zimmermann 12/2007 ATF collaboration meetings and IFIC-LAL-CERN meetings in Annecy, Geneva, Hamburg, Valencia and Paris (H. Braun, R. Tomas, F. Zimmermann); ATF TB & SGC meetings regular ATF2 and PosiPol phone meetings

19. CERN-KEK Committee 07/12/07J.P.Delahaye19 25% of ATF Reports in 2006 with CERN lead authors

20. CERN-KEK Committee 07/12/07J.P.Delahaye20 CERN-IFIC-LAL-UK collaboration on ATF participants: P. Bambade (LAL), A. Faus-Golfe (IFIC), R. Tomas, F. Zimmermann (CERN), R. Appleby (CI); >4 PhD students and postdocs anomalous current-dependent emittance growth between ring and extraction line; topics: four-dimensional emittance diagnostics in the extraction line bi-monthly meetings and discussions first beam studies in November/December 2007

21. CERN-KEK Committee 07/12/07J.P.Delahaye21 additional future collaboration subjects beam halo studies IBS effects (bunch shape & tails) flight simulator code comparisons Compton e+ stacking studies

22. CERN-KEK Committee 07/12/07J.P.Delahaye22 polarized e+/e- source based on laser Compton back scattering M. Kuriki, T. Omori, J. Urakawa, KEK K. Moenig, A. Variola, F. Zomer, LAL E. Bulyak, P. Gladkikh, NSC KIPT  highly polarized e + and e - (>90%);  fully independent e+ generation Compton e- ring experimental verification at ATF (e.g. Phys.Rev.Lett.96:114801,2006)

23. CERN-KEK Committee 07/12/07J.P.Delahaye23 Draft of Collaborative agreement being prepared as a follow-up of visit@CERN of Prof Suzuki on 02/07/07

24. CERN-KEK Committee 07/12/07J.P.Delahaye24 Collaboration agreement "Agreement on Collaborative Work", under reference ICA- JP-0103. Two signature versions are at CERN with the Legal Service, awaiting green light by KEK for signature. Appendix 1: 2003 Memorandum concerning the Participation of Japanese Summer Students in the CERN Summer Student Programme Appendix 2: general “umbrella” for high-gradient studies & collaboration on High Gradient Accelerator Technology and Fabrication and Tests of X-Band Accelerating Structures Appendix 3 to Agreement on Collaborative Work: Design, fabrication and test of high gradient accelerating structures T18_vg2.4_disk and TD18_vg2.4_quad Appendix 4: next to be written, accelerating structures disk damped + next round of structures based on test results

25. CERN-KEK Committee 07/12/07J.P.Delahaye25 High-gradient accelerating structure production Objective of the collaboration: Both KEK and CERN in the past decade have been forerunners in the world for the R&D ’ s of high gradient acceleration on the basis of normal conducting accelerator structures. The objective of this collaboration is to facilitate further development of related key technologies, in particular the X-band technologies, by the two parties Technical contacts: –KEK: Yukihide Kamiya, Director of Accelerator Laboratory of KEK Toshiyasu Higo, Accelerator Laboratory of KEK Shigeki Fukuda, Accelerator Laboratory of KEK –CERN: Jean-Pierre Delahaye, CLIC study leader Walter Wuensch, CLIC structure leader Germana Riddone, CLIC structure production Steffen Doebert, CLIC structure testing

26. CERN-KEK Committee 07/12/07J.P.Delahaye26 Acceptable Breakdown Rate in linear collider operation not higher than 10-6 Reduction of accelerating field by about 30 MV/m for low BR with Cu Cu Mo CLIC High-Power tests various materials results @ 30 GHz CLIC operational goal

27. CERN-KEK Committee 07/12/07J.P.Delahaye27 The beauty of 12 GHz Close to maximum Performance and minimum Cost (14 GHz) Accelerating gradient of 100 MV/m already demonstrated at low breakdown rate with short pulse in non fully equipped structures Very close to the NLC and JLC frequency: 11.4 GHz –Building up on wide expertise and long-term R&D made during many years on warm structures, RF power sources, beam dynamics at SLAC and KEK –Take advantage of low(er than 30 GHz) frequency for easier fabrication (tolerances, vacuum), relaxed requirements (alignment, timing, etc…), RF power generation and frequency multiplication in CLIC TBA RF Power Source –High gradients achievable with short RF pulse provided by TBA RF power source –Easy adaptation of CTF3 (multiplication factor by 8 instead of 10) Stand alone power sources available: –Makes the best use of developments and equipments at SLAC and KEK

28. CERN-KEK Committee 07/12/07J.P.Delahaye28 X-band (11.4 GHz) Test Facilities at KEK Single Klystron (50 MW) test stand up and running NEXTEF: Available from fall 2007, 2x50 MW, 400 ns, 24/7 operation

29. CERN-KEK Committee 07/12/07J.P.Delahaye29 The state of the Art in x-band structures Final NLC/GLC prototype, fully equipped with higher order mode damping, a pair of these structures made by KEK was tested in the ASSET facility at SLAC to determine the wake fields and demonstrated the extremely high standards in precession machining achieved by KEK.

30. Tests of old NLC structures at short pulses T53vg3MC can be used as a first reference for the new CLIC parameters CLIC goal

31. CERN-KEK Committee 07/12/07J.P.Delahaye31

32. CERN-KEK Committee 07/12/07J.P.Delahaye32 Near future accelerating structures T18_VG2.4_disk (disk undamped): 3 structures –Objective: to use JLC espertise in structure fabrication to study a structure with rf parameters close to nominale ones, huigh quality data by testing multilple structures (a forth structure will be fabricated by EU company and tested at CERN) –#1, #2: fabrication of disks by KEK, delivered to SLAC, ready for bonding, then tested at SLAC and KEK –#3: all made and tested by KEK TD18_VG2.4_quad (quadrant damped): one structure –Objective: learn about quadrant fabrication and assembly –Test cutting by 5 companies: HITACHI, I I C, YASDA, Morikawa, U-corporation –Select one company to make a prototype quadrant –Fabrication of one full structure –Test full structure at KEK June-07 to May-08 (test not included) July 07 to June-08 (test not included) Red: to be done

33. CERN-KEK Committee 07/12/07J.P.Delahaye33 Kek’s schedule for structure testing using the NEXTEF facility

34. CERN-KEK Committee 07/12/07J.P.Delahaye34 T18_VG2.4_disk Structure elements for #1 and #2 Bead pull system for rf measurements

35. CERN-KEK Committee 07/12/07J.P.Delahaye35 Input matching and transmission in clamped T18_VG2.4_disk (#1 and #2) cavity Very good performance!

36. CERN-KEK Committee 07/12/07J.P.Delahaye36 TD18_VG2.4_quad 3D dimensional control under way Test piece received in Nov 2007

37. CERN-KEK Committee 07/12/07J.P.Delahaye37 Conclusion ~Excellent collaboration between CERN and KEK about Linear Colliders & CLIC related activities: ATF 1,2 @ KEK: –Strong CERN involvement –microrad beam emittances,nm spot sizes & nm stability crucial for CLIC –looking forward to <40 nm spot sizes in 2008/09! High Gradient RF structures R&D –Excellent KEK expertise and vital contribution –CERN/KEK/SLAC fruitful collaboration –Fabrication and tests of RF structures on existing Test stands –Participation in RF designs –looking forward to > 100 MV/m accelerating gradient in 2008/09! Possible future collaboration: –More exchange of exoperts and visits –Modulator development: one KEK expert on CTF3 modulator for one year –High power X band klystron developments –Number of R&D subjects in the frame of CERN-Japan fellowship program