The ILC Global Design Effort

1. The ILC Global Design Effort Barry Barish SPC Meeting CERN 13-Aug-05

2. Why a TeV Scale e+e- Accelerator? • Two parallel developments over the past few years (the science & the technology) • The precision information from LEP and other data have pointed to a low mass Higgs; Understanding electroweak symmetry breaking, whether supersymmetry or an alternative, will require precision measurements. • There are strong arguments for the complementarity between a ~0.5-1.0 TeV LC and the LHC science. Scientific Policy Committee - CERN

3. Electroweak Precision Measurements LEP results strongly point to a low mass Higgs and an energy scale for new physics < 1TeV Scientific Policy Committee - CERN

4. Why a TeV Scale e+e- Accelerator? • Two parallel developments over the past few years (the science & the technology) • The precision information from LEP and other data have pointed to a low mass Higgs; Understanding electroweak symmetry breaking, whether supersymmetry or an alternative, will require precision measurements. • There are strong arguments for the complementarity between a ~0.5-1.0 TeV LC and the LHC science. Scientific Policy Committee - CERN

5. LHC/ILC Complementarity The 500 GeV Linear Collider Spin Measurement LHC should discover the Higgs The linear collider will measure the spin of any Higgs it can produce. The Higgs must have spin zero The process e+e–HZ can be used to measure the spin of a 120 GeV Higgs particle. The error bars are based on 20 fb–1 of luminosity at each point. Scientific Policy Committee - CERN

6. Linear collider LHC/ILC Complementarity Extra Dimensions New space-time dimensions can be mapped by studying the emission of gravitons into the extra dimensions, together with a photon or jets emitted into the normal dimensions. Scientific Policy Committee - CERN

7. Why a TeV Scale e+e- Accelerator? • Two parallel developments over the past few years (the science & the technology) • Two alternate designs -- “warm” and “cold” had come to the stage where the show stoppers had been eliminated and the concepts were well understood. • A major step toward a new international machine requires uniting behind one technology, and then make a unified global design based on the recommended technology. Scientific Policy Committee - CERN

8. TESLA Concept • The main linacs based on 1.3 GHz superconducting technology operating at 2 K. • The cryoplant, is of a size comparable to that of the LHC, consisting of seven subsystems strung along the machines every 5 km. Scientific Policy Committee - CERN

9. The JLC-X and NLC are essentially a unified single design with common parameters • The main linacs are based on 11.4 GHz, room temperature copper technology. GLC GLC/NLC Concept Scientific Policy Committee - CERN

10. Which Technology to Choose? • Two alternate designs -- “warm” and “cold” had come to the stage where the show stoppers had been eliminated and the concepts were well understood. • A major step toward a new international machine requires uniting behind one technology, and then make a unified global design based on the recommended technology. Scientific Policy Committee - CERN

11. The ITRP Recommendation • We recommend that the linear collider be based on superconducting rf technology • This recommendation is made with the understanding that we are recommending a technology, not a design. We expect the final design to be developed by a team drawn from the combined warm and cold linear collider communities, taking full advantage of the experience and expertise of both(from the Executive Summary). Scientific Policy Committee - CERN

12. SCRF Technology Recommendation • The recommendation of ITRP was presented to ILCSC & ICFA on August 19, 2004 in a joint meeting in Beijing. • ICFA unanimously endorsed the ITRP’s recommendation on August 20, 2004 Scientific Policy Committee - CERN

13. The Community Self-Organized Nov 13-15, 2004 Scientific Policy Committee - CERN

14. WG1 Parms & layout WG2 Linac WG3 Injectors WG4 Beam Delivery WG5 High Grad. SCRF WG6 Communications WG1 LET beam dynamics WG2 Main Linac WG3a Sources WG3b Damping Rings WG4 Beam Delivery WG5 SCRF Cavity Package WG6 Communications KEK Workshop Organization Birth of the GDE and Preparation for Snowmass Scientific Policy Committee - CERN

15. Global Design Effort • The Mission of the GDE • Produce a design for the ILC that includes a detailed design concept, performance assessments, reliable international costing, an industrialization plan , siting analysis, as well as detector concepts and scope. • Coordinate worldwide prioritized proposal driven R & D efforts (to demonstrate and improve the performance, reduce the costs, attain the required reliability, etc.) Scientific Policy Committee - CERN

16. Chris Adolphsen, SLAC Jean-Luc Baldy, CERN Philip Bambade, LAL, Orsay Barry Barish, Caltech Wilhelm Bialowons, DESY Grahame Blair, Royal Holloway Jim Brau, University of Oregon Karsten Buesser, DESY Elizabeth Clements, Fermilab Michael Danilov, ITEP Jean-Pierre Delahaye, CERN, Gerald Dugan, Cornell University Atsushi Enomoto, KEK Brian Foster, Oxford University Warren Funk, JLAB Jie Gao, IHEP Terry Garvey, LAL-IN2P3 Hitoshi Hayano, KEK Tom Himel, SLAC Bob Kephart, Fermilab Eun San Kim, Pohang Acc Lab Hyoung Suk Kim, Kyungpook Nat’l Univ Shane Koscielniak, TRIUMF Vic Kuchler, Fermilab Lutz Lilje, DESY Tom Markiewicz, SLAC David Miller, Univ College of London Shekhar Mishra, Fermilab Youhei Morita, KEK Olivier Napoly, CEA-Saclay Hasan Padamsee, Cornell University Carlo Pagani, DESY Nan Phinney, SLAC Dieter Proch, DESY Pantaleo Raimondi, INFN Tor Raubenheimer, SLAC Francois Richard, LAL-IN2P3 Perrine Royole-Degieux, GDE/LAL Kenji Saito, KEK Daniel Schulte, CERN Tetsuo Shidara, KEK Sasha Skrinsky, Budker Institute Fumihiko Takasaki, KEK Laurent Jean Tavian, CERN Nobu Toge, KEK Nick Walker, DESY Andy Wolski, LBL Hitoshi Yamamoto, Tohoku Univ Kaoru Yokoya, KEK 49 members GDE Members Americas 16 Europe 21 Asia 12 Scientific Policy Committee - CERN

17. Participation in Snowmass 670 Scientists attended two week workshop at Snowmass Scientific Policy Committee - CERN

18. WG1 LET bdyn. WG2 Main Linac WG3a Sources WG3b DR WG4 BDS WG5 Cavity GG1 Parameters GG2 Instrumentation GG3 Operations & Reliability GG4 Cost & Engineering GG5 Conventional Facilities GG6 Physics Options GDE Organization for Snowmass) Technical sub-system Working Groups Provide input Global Group Scientific Policy Committee - CERN

19. 2005 2006 2007 2008 2009 2010 CLIC Global Design Effort Project LHC Physics Baseline configuration Reference Design The GDE Plan and Schedule Technical Design ILC R&D Program Expression of Interest to Host International Mgmt

20. Starting Point for the GDE Superconducting RF Main Linac Scientific Policy Committee - CERN

21. Parameters for the ILC • Ecm adjustable from 200 – 500 GeV • Luminosity ∫Ldt = 500 fb-1 in 4 years • Ability to scan between 200 and 500 GeV • Energy stability and precision below 0.1% • Electron polarization of at least 80% • The machine must be upgradeable to 1 TeV Scientific Policy Committee - CERN

22. Higgs Coupling and Extra Dimensions • ILC precisely measures Higgs interaction strength with standard model particles. • Straight blue line gives the standard model predictions. • Range of predictions in models with extra dimensions -- yellow band, (at most 30% below the Standard Model • The models predict that the effect on each particle would be exactly the same size. • The red error bars indicate the level of precision attainable at the ILC for each particle • Sufficient to discover extra dimensional physics. Scientific Policy Committee - CERN

23. Design Approach • Create a baseline configuration for the machine • Document a concept for ILC machine with a complete layout, parameters etc. defined by the end of 2005 • Make forward looking choices, consistent with attaining performance goals, and understood well enough to do a conceptual design and reliable costing by end of 2006. • Technical and cost considerations will be an integral part in making these choices. • Baseline will be put under “configuration control,” with a defined process for changes to the baseline. • A reference design will be carried out in 2006. I am proposing we use a “parametric” design and costing approach. • Technical performance and physics performance will be evaluated for the reference design Scientific Policy Committee - CERN

24. Parametric Approach • Parametric approach to design • machine parameters : a space to optimize the machine • Trial parameter space, being evaluated by subsystems • machine design : incorporate change without redesign; incorporates value engineering, trade studies at each step to minimize costs Scientific Policy Committee - CERN

25. Approach to ILC R&D Program • Proposal-driven R&D in support of the baseline design. • Technical developments, demonstration experiments, industrialization, etc. • Proposal-driven R&D in support of alternatives to the baseline • Proposals for potential improvements to the baseline, resources required, time scale, etc. • Develop a prioritized DETECTOR R&D program aimed at technical developments needed to reach combined design performance goals Scientific Policy Committee - CERN

26. The Key Decisions Critical choices: luminosity parameters & gradient Scientific Policy Committee - CERN

27. Cost Drivers Civil SCRF Linac Scientific Policy Committee - CERN

28. What Gradient to Choose? Scientific Policy Committee - CERN

29. How Costs Scale with Gradient? 35MV/m is close to optimum Japanese are still pushing for 40-45MV/m 30 MV/m would give safety margin Relative Cost Gradient MV/m C. Adolphsen (SLAC) Scientific Policy Committee - CERN

30. Cavity Fabrication Scientific Policy Committee - CERN

31. Gradient Results from KEK-DESY collaboration must reduce spread (need more statistics) single-cell measurements (in nine-cell cavities) Scientific Policy Committee - CERN

32. Improved Fabrication Scientific Policy Committee - CERN

33. Improved ProcessingElectropolishing Scientific Policy Committee - CERN

34. Electro-polishing (Improve surface quality -- pioneering work done at KEK) BCP EP • Several single cell cavities at g > 40 MV/m • 4 nine-cell cavities at ~35 MV/m, one at 40 MV/m • Theoretical Limit 50 MV/m Scientific Policy Committee - CERN

35. Baseline Gradient Scientific Policy Committee - CERN

36. Improved Cavity Shapes Scientific Policy Committee - CERN

37. Large Grain Single Crystal Nb Material Scientific Policy Committee - CERN

38. ILC Siting and Civil Construction • The design is intimately tied to the features of the site • 1 tunnels or 2 tunnels? • Deep or shallow? • Laser straight linac or follow earth’s curvature in segments? • GDE ILC Design will be done to samples sites in the three regions • North American sample site will be near Fermilab • Japan choosing between three final sites • Europe sample sites --- CERN and DESY Scientific Policy Committee - CERN

39. 1 vs 2 Tunnels • Tunnel must contain • Linac Cryomodule • RF system • Damping Ring Lines • Save maybe $0.5B • Issues • Maintenance • Safety • Duty Cycle Scientific Policy Committee - CERN

40. Possible Tunnel Configurations • One tunnel of two, with variants ?? Scientific Policy Committee - CERN

41. ILC Civil Program Civil engineers from all three regions working to develop methods of analyzing the siting issues and comparing sites. The current effort is not intended to select a potential site, but rather to understand from the beginning how the features of sites will effect the design, performance and cost Scientific Policy Committee - CERN

42. Toshiba Thales CPI Baseline Klystrons Available today: 10 MW Multi-Beam Klystrons (MBKs) that operate at up to 10 Hz Scientific Policy Committee - CERN

43. Improved Klystron ? 5 MW Inductive Output Tube (IOT) 10 MW Sheet Beam Klystron (SBK) Low Voltage 10 MW MBK Parameters similar to 10 MW MBK Voltage e.g. 65 kV Current 238A More beams Perhaps use a Direct Switch Modulator Klystron Output IOT KEK SLAC CPI Drive Scientific Policy Committee - CERN

44. RF Distribution BASELINE DESIGN Similar to TDR and XFEL scheme. POSSIBLE IMPROVEMENT? With two-level power division and proper phase lengths, expensive circulators can be eliminated. Reflections from pairs of cavities are directed to loads. Also, fewer types of hybrid couplers are needed in this scheme. There is a small increased risk to klystrons. (Total reflection from a pair of cavities sends < 0.7% of klystron power back to the klystron.) Scientific Policy Committee - CERN

45. Beamsize Growth Study (cumulative after feedback) + Kicker, current, energy jitter, BPM resol. + 5 Hz ground. + Component jitter + Undulator 30 min ground. Scientific Policy Committee - CERN

46. Availability Studies1 vs 2 tunnels Scientific Policy Committee - CERN

47. Improving Mean Time Between Failures Scientific Policy Committee - CERN

48. Damping Rings: Three variants 6km 3km 17 km ‘dogbone’ Scientific Policy Committee - CERN

49. Beam Delivery, MDI • Strawman solution (BCD recommendation) • Appears to work for nearly all suggested parameter sets: • Exceptions: • 1 TeV high-luminosity (new parameter set suggested for 20mrad) • 2 mrad extraction has problems with high disruption sets Scientific Policy Committee - CERN

50. Industrial Studies • Industrial studies in three regions are essential. • Important to understand industrial costs • Important to examine potential cost reductions • Need to think about what studies are needed and when • Focus on the cost drivers for ILC, important for cost estimate • Focus on places where there is technical risk to the project goals • ILC need a point-of-contact and a plan for industrial studies 2nd ILC Industrial Forum Meeting is scheduled to be held at Fermilab Sept. 21st and 22nd, 2005. Scientific Policy Committee - CERN