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

13-Sept-05Scientific Policy Committee - CERN2 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 ~ TeV LC and the LHC science.

13-Sept-05Scientific Policy Committee - CERN3 Electroweak Precision Measurements LEP results strongly point to a low mass Higgs and an energy scale for new physics < 1TeV

13-Sept-05Scientific Policy Committee - CERN4 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 ~ TeV LC and the LHC science.

13-Sept-05Scientific Policy Committee - CERN5 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 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. LHC/ILC Complementarity The Higgs must have spin zero

13-Sept-05Scientific Policy Committee - CERN6 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. Linear collider LHC/ILC Complementarity

13-Sept-05Scientific Policy Committee - CERN7 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.

13-Sept-05Scientific Policy Committee - CERN8 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.

13-Sept-05Scientific Policy Committee - CERN9 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

13-Sept-05Scientific Policy Committee - CERN10 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.

13-Sept-05Scientific Policy Committee - CERN11 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).

13-Sept-05Scientific Policy Committee - CERN12 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

13-Sept-05Scientific Policy Committee - CERN13 The Community Self-Organized Nov 13-15, 2004

13-Sept-05Scientific Policy Committee - CERN14 KEK Workshop Organization 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 Birth of the GDE and Preparation for Snowmass

13-Sept-05Scientific Policy Committee - CERN15 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.)

13-Sept-05Scientific Policy Committee - CERN16 GDE Members 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 Americas 16 Europe 21 Asia 12

13-Sept-05Scientific Policy Committee - CERN17 Participation in Snowmass 670 Scientists attended two week workshop at Snowmass

13-Sept-05Scientific Policy Committee - CERN18 GDE Organization for Snowmass) 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 Technical sub-system Working Groups Global Group Provide input

The GDE Plan and Schedule Global Design EffortProject Baseline configuration Reference Design ILC R&D Program Technical Design Expression of Interest to Host International Mgmt LHC Physics CLIC

13-Sept-05Scientific Policy Committee - CERN20 Starting Point for the GDE Superconducting RF Main Linac

13-Sept-05Scientific Policy Committee - CERN21 Parameters for the ILC E cm 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

13-Sept-05Scientific Policy Committee - CERN22 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.

13-Sept-05Scientific Policy Committee - CERN23 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 –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 I am proposing we use a “parametric” design and costing approach. –Technical performance and physics performance will be evaluated for the reference design

13-Sept-05Scientific Policy Committee - CERN24 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

13-Sept-05Scientific Policy Committee - CERN25 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

13-Sept-05Scientific Policy Committee - CERN26 The Key Decisions Critical choices: luminosity parameters & gradient

13-Sept-05Scientific Policy Committee - CERN27 Cost Drivers Civil SCRF Linac

13-Sept-05Scientific Policy Committee - CERN28 What Gradient to Choose?

13-Sept-05Scientific Policy Committee - CERN29 How Costs Scale with Gradient? Relative Cost Gradient MV/m 35MV/m is close to optimum Japanese are still pushing for MV/m 30 MV/m would give safety margin C. Adolphsen (SLAC)

13-Sept-05Scientific Policy Committee - CERN30 Cavity Fabrication

13-Sept-05Scientific Policy Committee - CERN31 Gradient Results from KEK-DESY collaboration must reduce spread (need more statistics) single-cell measurements (in nine-cell cavities)

13-Sept-05Scientific Policy Committee - CERN32 Improved Fabrication

13-Sept-05Scientific Policy Committee - CERN33 Improved Processing Electropolishing

13-Sept-05Scientific Policy Committee - CERN34 (Improve surface quality -- pioneering work done at KEK) BCPEP 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 Electro-polishing

13-Sept-05Scientific Policy Committee - CERN35 Baseline Gradient

13-Sept-05Scientific Policy Committee - CERN36 Improved Cavity Shapes

13-Sept-05Scientific Policy Committee - CERN37 Large Grain Single Crystal Nb Material

13-Sept-05Scientific Policy Committee - CERN38 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

13-Sept-05Scientific Policy Committee - CERN39 1 vs 2 Tunnels Tunnel must contain –Linac Cryomodule –RF system –Damping Ring Lines Save maybe $0.5B Issues –Maintenance –Safety –Duty Cycle

13-Sept-05Scientific Policy Committee - CERN40 Possible Tunnel Configurations One tunnel of two, with variants ??

13-Sept-05Scientific Policy Committee - CERN41 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

13-Sept-05Scientific Policy Committee - CERN42 Baseline Klystrons Thales CPI Toshiba Available today: 10 MW Multi-Beam Klystrons (MBKs) that operate at up to 10 Hz

13-Sept-05Scientific Policy Committee - CERN43 Improved Klystron ? 10 MW Sheet Beam Klystron (SBK) Parameters similar to 10 MW MBK Low Voltage 10 MW MBK Voltage e.g. 65 kV Current 238A More beams Perhaps use a Direct Switch Modulator 5 MW Inductive Output Tube (IOT) Drive Output IOT Klystron SLAC CPI KEK

13-Sept-05Scientific Policy Committee - CERN44 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.) Similar to TDR and XFEL scheme. BASELINE DESIGN POSSIBLE IMPROVEMENT? RF Distribution

13-Sept-05Scientific Policy Committee - CERN45 Beamsize Growth Study (cumulative after feedback) 30 min ground. + Undulator + Component jitter + 5 Hz ground. + Kicker, current, energy jitter, BPM resol.

13-Sept-05Scientific Policy Committee - CERN46 Availability Studies 1 vs 2 tunnels

13-Sept-05Scientific Policy Committee - CERN47 Improving Mean Time Between Failures

13-Sept-05Scientific Policy Committee - CERN48 Damping Rings: Three variants 3km 6km 17 km ‘dogbone’

13-Sept-05Scientific Policy Committee - CERN49 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

13-Sept-05Scientific Policy Committee - CERN50 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 2 nd ILC Industrial Forum Meeting is scheduled to be held at Fermilab Sept. 21 st and 22 nd, 2005.

13-Sept-05Scientific Policy Committee - CERN51 Three concepts under study Typically requires factors of two or so improvements in granularity, resolution, etc. from present generation detectors Focused R&D program required to develop the detectors -- end of 2005 Detector Concepts will be used to simulate performance of reference design vs physics goals next year. Detector Concepts and Challenges

13-Sept-05Scientific Policy Committee - CERN52 Accelerator Physics Challenges Develop High Gradient Superconducting RF systems –Requires efficient RF systems, capable of accelerating high power beams (~MW) with small beam spots(~nm). Achieving nm scale beam spots –Requires generating high intensity beams of electrons and positrons –Damping the beams to ultra-low emittance in damping rings –Transporting the beams to the collision point without significant emittance growth or uncontrolled beam jitter –Cleanly dumping the used beams. Reaching Luminosity Requirements –Designs satisfy the luminosity goals in simulations –A number of challenging problems in accelerator physics and technology must be solved, however.

13-Sept-05Scientific Policy Committee - CERN53 Creating an International Project Several Studies and Plans for ILC –OECD (Organization for Economic Cooperation and Development) “A template for Establishing, Funding and Managing an International Scientific Research Project Based on an Agreement Between Governments and Institutions” –Features a template that covers all aspects of creating agreements for an international collaboration, in particular formal agreements, funding arrangements, central structure and using existing institutions

13-Sept-05Scientific Policy Committee - CERN54 OECD International Project Template

13-Sept-05Scientific Policy Committee - CERN55 Creating an International Project Several Studies and Plans for ILC –TESLA proposed plan for Project Organization “Organization and Management of an International Collaboration on the TESLA Linear Collider” –Features a “Global Accelerator Network”, which is basically a collaboration between institutions where as much as possible the participation is treated as an extension of the laboratory programs and even the accelerator is to be run locally from the collaborating laboratories.

13-Sept-05Scientific Policy Committee - CERN56 TESLA Proposed Project Organization

13-Sept-05Scientific Policy Committee - CERN57 Creating an International Project Several Studies and Plans for ILC –ECFA EUROPEAN COMMITTEE FOR FUTURE ACCELERATORS subcomittee EUROPEAN LINEAR COLLIDER STEERING GROUP “Report of the Sub-group on Organizational Matters” –Features a detailed breakdown of top level governance and project management, how they relate to each other. It is based on regional organizations; mostly in-kind contributions; shared central management, oversight, responsibility. It is concerned with Europe and how to do it within European Labs (CERN) and structures

13-Sept-05Scientific Policy Committee - CERN58 ECFA ILC Governance and Management

13-Sept-05Scientific Policy Committee - CERN59 Remarkable progress in the past two years toward realizing an international linear collider: important R&D on accelerator systems definition of parameters for physics choice of technology start the global design effort funding agencies are engaged  Many major hurdles remain before the ILC becomes a reality (funding, site, international organization, and most importantly, a technical design and construction plan)  The time scale for ILC project readiness is consistent with early results from LHC and CLIC feasability studies. Conclusions