International Linear Collider Technical Review Committee Nick Walker (DESY)

1. International Linear ColliderTechnical Review Committee Nick Walker (DESY)

2. Where is The Report? Available online: http://www.slac.stanford.edu/xorg/ilc-trc/2002/2002/report/03rep.htm Printed and CD-ROM versions should be available soon (now?) 420 pages!

3. History of the ILC-TRC • International Collaboration for R&D toward TeV-Scale e +e– LC asked for first ILC-TRC in June 1994 • ILC-TRC produced first report end of 1995 • 2001: ICFA requests that ILC-TRC reconvene to produce a second report (subject of this talk)

4. Second ILC-TRC Charge • To assess the present technology status of the four LC designs at hand, and their potential for meeting the advertised parameters at 500 GeV c.m. • Use common criteria, definitions, computer codes, etc., for the assessments

5. Second ILC-TRC Charge • To assess the potential of each design for reaching higher energies above500 GeV c.m. • To establish, for each design, the R&D work that remains to be done in the next few years • To suggest future areas of collaboration

6. LC Status at First TRC 1994 Ecm=500 GeV

7. LC Status at Second TRC 2003 Ecm=500 GeV

8. Steering Committee Reinhard Brinkmann (DESY) Kaoru Yokoya (KEK) Tor Raubenheimer (SLAC) Gilbert Guignard (CERN) WG I Technology, RF Power, and Energy Performance Assessment WG II Luminosity Performance Assessment Organisation Chair Greg Loew (SLAC)

9. WG I Technology, RF Power, and Energy Performance Assessment WG II Luminosity Performance Assessment WG III Reliability, Availability and Operability Organisation Chair Greg Loew (SLAC) Steering Committee

10. Technology Working Group ChairDaniel Boussard (CERN) MembersC. Adolphsen (SLAC)H. Braun (CERN)H. Edwards (FNAL)K. Hubner (CERN)L. Lilje (DESY)P. Logatchov (BINP)R. Pasquinelli (FNAL)M. Ross (SLAC)T. Schintake (KEK)N. Toge (KEK)H. Weise (DESY)P. Wilson (SLAC) • Injector, DR, and BDS • Power Sources • klystrons, power supplies, modulators, low level RF etc. • Power Distribution • RF pulse compression, waveguides, two-beam acceleration (CLIC) etc. • Accelerator Structures

11. Luminosity Working Group ChairGerry Dugen (Cornell) MembersR. Assmann (CERN)W. Decking (DESY)J. Gareyte (CERN)K. Kubo (KEK)W. Kozanecki (Saclay)N. Phiney (SLAC)J. Rogers (Cornell)D. Schulte (CERN)A. Seryi (SLAC)R. Settles (MPI)P. Tenenbaum (SLAC)N. Walker (DESY)A. Wolski (LBNL) • e± Sources (gun  DR) • DR • Low Emittance Transport (LET, from DR  IP) • bunch compressors • main linac • beam delivery • Machine Detector Interface Many new studies (simulations) performed THIS was much more than a review!

12. Reliability Working Group Co-ChairsRalph Pasquinelli (FNAL)Nan Phinney (SLAC) MembersC. Adolphsen (SLAC)Y. Chin (KEK)H. Edwards (FNAL)K. Hubner (CERN)L. Lilje (DESY)M. Ross (SLAC)N. Toge (KEK)H. Weise (DESY) R. Assmann (CERN)W. Kozanecki (Saclay)D. Schulte (CERN)A. Seryi (SLAC)P. Tenenbaum (SLAC)N. Walker (DESY) • Reliability • hardware components • MTBF • Availability • fraction of time available for delivering luminosity • Operability • impact of (invasive) tuning, machine studies etc. technology luminosity

13. 2nd TRC Time-Line • Summer 2001: ICFA requests report • Autumn 2001: WGs formed • 2002 WGs meet 4 times during the year to • define tasks • review progress • formulate summary • October 2002: Greg Loew formally reports findings at ICFA seminar • January 2003: Published! Many many video/telephone conferences (Tbytes of email!)

14. Methodology • Review current designs and status (achievements) of R&D, particularly the test facilities • Identify the positive aspects of the designs • Identify those areas of ‘concern’ and • identify R&D that needs to be done to address these issues • Categorise (rank) the R&D items

15. The Rankings for R&D • Ranking 1 • Ranking 2 • Ranking 3 • Ranking 4

16. The Rankings for R&D • Ranking 1 • Ranking 2 • Ranking 3 • Ranking 4 R&D needed for feasibility demonstration of the machine what you must do before you can honestly say the machine will work (proof of principle)

17. The Rankings for R&D • Ranking 1 • Ranking 2 • Ranking 3 • Ranking 4 R&D needed to finalize design choices and ensure reliability Still critical R&D, but not central to proof of principle Not mandatory before formal proposal

18. The Rankings for R&D • Ranking 1 • Ranking 2 • Ranking 3 • Ranking 4 R&D needed before starting production of systems and components Necessary engineering (prototyping) before (for example) transferring to industry (mass production)

19. The Rankings for R&D • Ranking 1 • Ranking 2 • Ranking 3 • Ranking 4 R&D desirable for technical or cost optimisation Would be useful to do but is not strictly mandatory Basically all things that ‘fell off the list’ for R1-3

20. Rankings Score Sheet

21. The Specific R1 Items • TESLA • JLC-C • NLC/JLC-X • CLIC

22. The Specific R1 Items • TESLA • JLC-C • NLC/JLC-X • CLIC • Ecm = 800 GeVBuilding and testing of a cryomodule at 35 MV/m and measurements of dark current • Requires the module test stand • Delayed by budget constraints • Very unlikely to happen before 2005! However, the push to Ez>35 MV/m continues…

23. TESLA High-Gradient R&D • High gradients good for X-Ray FEL too

24. TESLA 800 goal TESLA High-Gradient R&D • High gradients good for X-Ray FEL too • Electro-polishing programme on-going and considered best for mass-production

25. Beam on TESLA High-Gradient R&D • High gradients good for X-Ray FEL too • Electro-polishing programme on-going and considered best for mass-production • Fast piezo cavity tuner to compensate Lorentz force detuning

26. The Specific R1 Items • TESLA • JLC-C • NLC/JLC-X • CLIC • Ecm = 500 GeVHigh power tests of of C-band choke-mode and dark current • Ecm = 500 GeVDemonstration of SLED-II pulse compressor at full power

27. The Specific R1 Items • TESLA • JLC-C • NLC/JLC-X • CLIC • Ecm = 500 GeVTest of complete accelerator structure at design gradient with detuning and damping, including study of breakdown and dark current • Ecm = 500 GeV Demonstration of SLED-II pulse compressor at full power Goal: end of 2003 for proof of principle tests

28. The Specific R1 Items • TESLA • JLC-C • NLC/JLC-X • CLIC • Test existing structures at 130ns pulse length and design gradient. • High power tests of structures with wakefield damping • design and test of switchable power extraction transfer structures • Validation of drive beam generation with fully loaded linac • full test of a basic hardware unit (at reduce length) Many basic questions as expected for an R&D project

29. The R2 Items • Damping Rings • Electron cloud effects • fast ion instabilities • Extraction kicker stability • Tuning simulations • LET • Static tuning studies • girder/cryomodule prototypes to study stability (vibration) • Critical beam instrumentation • Reliability • Detailed evaluation of critical sub-systems reliability Common items related to all designs

30. TTF-II, X-FEL TESLA R2 • Test of complete main linac RF sub-unit(as described in TDR) with beam • Tests of several cryomodules running at gradient 23.4 MV/m for a prolonged period of time • quench rates, breakdowns, dark current

31. TESLA R2 • Test of complete main linac RF sub-unit(as described in TDR) with beam • Tests of several cryomodules running at gradient 23.4 MV/m for a prolonged period of time • quench rates, breakdowns, dark current • One versus two tunnels (reliability) • DR dynamic aperture • wiggler end fields • need to minimise injection losses (Pinj=220kW) • DR kicker development • Head-on versus crossing angle • extraction lines issues

32. JLC-X/NLC R2 • Test of complete X-band main linac RF sub-unit (as described in baseline design) with beam • Full test of KEK 75 MW 1.6ms PPM klystron at 150/120 Hz • Full test of SLAC induction modulator

33. 8-Pack Project • Used 450MW klystrons • Drive NLC ready structures in NLCTA • End 2003

34. R3 • To some extent fine tuning R2 requirements • Much detailed work which (eventually) must be done • Examples (TESLA): • Backgrounds and collimation • Impact of positron scheme on commissioning/operability • LLRF (needs to be ‘robust’) • single tunnel noise sources

35. The Positive Side Rankings reflect the concerns of the working groups But TRC overall findings were extremely positive The ILC-TRC “did not find any insurmountable obstacle to building TESLA, JLC-C, JLC-X/NLC within the next few years…” executive summary

36. The Positive Side Rankings reflect the concerns of the working groups But TRC overall findings were extremely positive The ILC-TRC “also noted that the TESLA linac RF technology for 500 GeV c.m. is the most mature.” executive summary

37. The Positive Side Rankings reflect the concerns of the working groups But TRC overall findings were extremely positive The ILC-TRC concluded that Assuming the R1s are demonstrated (hopefully) by the end of 2003, the RF systems of the two machines will be on an equal footing… executive summary

38. The Positive Side Rankings reflect the concerns of the working groups But TRC overall findings were extremely positive The ILC-TRC concluded that At that time, the HEP community should make a choice based on the technical differences of the two machines reflected by the R2 issues executive summary

39. The Manpower & Money Problem The R1-4 issues are important but they need money and manpower to resolve The TESLA collaboration has limited (sub-critical) resources to address the R2 items (not related to the linac technologies) on any immediate time scale X-FEL has linac technology in hand

40. Final Comments • The TRC is a excellent example of what we can achieve when the LC accelerator communities work together • Attempts to maintain the ‘momentum’ post TRC are dwindling • Need guidance (mandate?) from ILCSC and the support of lab management to continue this collaborative work • Need More People!