The International Linear Collider Barry Barish 9-Nov-05

Particle Physics Inquiry Based Science Are there undiscovered principles of nature: New symmetries, new physical laws? How can we solve the mystery of dark energy? Are there extra dimensions of space? Do all the forces become one? Why are there so many kinds of particles? What is dark matter? How can we make it in the laboratory? What are neutrinos telling us? How did the universe come to be? What happened to the antimatter? from the Quantum Universe 9-Nov-05 LAL Orsay Seminar

Answering the Questions Three Complementary Probes Neutrinos as a Probe Particle physics and astrophysics using a weakly interacting probe High Energy Proton Proton Colliders Opening up a new energy frontier ( ~ 1 TeV scale) High Energy Electron Positron Colliders Precision Physics at the new energy frontier 9-Nov-05 LAL Orsay Seminar

Neutrinos observed from the sun ! Koshiba 41H  4He + 2e+ + 2 ve + energy Davis and Bahcall SuperKamiokande 9-Nov-05 LAL Orsay Seminar

But, too few neutrinos … If neutrinos have mass, then as conjectured earlier by Bruno Pontecorvo, neutrinos could “oscillate” from one type to another. In this case, some of the original electron neutrinos made in the sun convert to other neutrinos on trajectory to the earth 9-Nov-05 LAL Orsay Seminar

Puzzle resolved … neutrinos oscillate KamLAND used terrestrial neutrinos from reactors, observes oscillations SNO (Canada) used D20 to detect other neutrino types 9-Nov-05 LAL Orsay Seminar

Neutrinos – Some of the Dark Matter! Dark Energy 70% Cold Dark Matter 20% Hot Dark Matter (neutrinos) < 5% Ordinary (baryonic) Matter 5% 9-Nov-05 LAL Orsay Seminar

Neutrinos – The Future Long baseline neutrino experiments – Create neutrinos at an accelerator or reactor and study at long distance when they have oscillated from one type to another. MINOS Opera 9-Nov-05 LAL Orsay Seminar

Neutrinos – Many Questions Why are neutrino masses so small ? Are the neutrinos their own antiparticles? What is the separation and ordering of the masses of the neutrinos? Neutrinos contribution to the dark matter? CP violation in neutrinos, leptogenesis, possible role in the early universe and in understanding the particle antiparticle asymmetry in nature? 9-Nov-05 LAL Orsay Seminar

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 ILC and the LHC science. 9-Nov-05 LAL Orsay Seminar

Electroweak Precision Measurements What causes mass?? The mechanism – Higgs or alternative appears around the corner 9-Nov-05 LAL Orsay Seminar

CERN – Geneva Switzerland Accelerators and the Energy Frontier Large Hadron Collider CERN – Geneva Switzerland 9-Nov-05 LAL Orsay Seminar

LHC and the Energy Frontier Source of Particle Mass Discover the Higgs The Higgs Field Source of mass to all other particles The Higgs Field LEP fb-1 FNAL or variants or ??? 9-Nov-05 LAL Orsay Seminar

LHC and the Energy Frontier A New Force in Nature Discover a new heavy particle, Z’ Can show by measuring the couplings with the ILC how it relates to other particles and forces 9-Nov-05 LAL Orsay Seminar

This led to higher energy machines: Electron-Positron Colliders Bruno Touschek built the first successful electron-positron collider at Frascati, Italy (1960) Eventually, went up to 3 GeV ADA 9-Nov-05 LAL Orsay Seminar

But, not quite high enough energy …. 3.1 GeV Burt Richter Nobel Prize and Discovery Of Charm Particles SPEAR at SLAC 9-Nov-05 LAL Orsay Seminar

The rich history for e+e- continued as higher energies were achieved … DESY PETRA Collider 9-Nov-05 LAL Orsay Seminar

Electron Positron Colliders The Energy Frontier 9-Nov-05 LAL Orsay Seminar

Why e+e- Collisions ? elementary particles well-defined energy, angular momentum uses full COM energy produces particles democratically can mostly fully reconstruct events 9-Nov-05 LAL Orsay Seminar

How do you know you have discovered the Higgs ? Measure the quantum numbers. The Higgs must have spin zero ! The linear collider will measure the spin of any Higgs it can produce by measuring the energy dependence from threshold 9-Nov-05 LAL Orsay Seminar

What can we learn from the Higgs? Precision measurements of Higgs coupling can reveal extra dimensions in nature 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 red error bars indicate the level of precision attainable at the ILC for each particle 9-Nov-05 LAL Orsay Seminar

Direct production from extra dimensions ? Linear collider 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. 9-Nov-05 LAL Orsay Seminar

Is There a New Symmetry in Nature? Supersymmetry Bosons Fermions Virtues of Supersymmetry: Unification of Forces The Hierarchy Problem Dark Matter … 9-Nov-05 LAL Orsay Seminar

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 9-Nov-05 LAL Orsay Seminar

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. 9-Nov-05 LAL Orsay Seminar

The JLC-X and NLC essentially a unified single design with common parameters The main linacs based on 11.4 GHz, room temperature copper technology. GLC GLC/NLC Concept 9-Nov-05 LAL Orsay Seminar

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. 9-Nov-05 LAL Orsay Seminar

CLIC Concept Drive Beam The main linac rf power is produced by decelerating a high-current (150 A) low-energy (2.1 GeV) drive beam Nominal accelerating gradient of 150 MV/m GOAL Proof of concept ~2010 Main Accelerator 9-Nov-05 LAL Orsay Seminar

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 9-Nov-05 LAL Orsay Seminar

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). 9-Nov-05 LAL Orsay Seminar

The Community Self-Organized Nov 13-15, 2004 9-Nov-05 LAL Orsay Seminar

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.) 9-Nov-05 LAL Orsay Seminar

GDE Members Americas 16 Europe 21 Asia 12 49 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 9-Nov-05 LAL Orsay Seminar

Designing a Linear Collider Superconducting RF Main Linac 9-Nov-05 LAL Orsay Seminar

Specific Machine Realizations rf bands: L-band (TESLA) 1.3 GHz l = 3.7 cm S-band (SLAC linac) 2.856 GHz 1.7 cm C-band (JLC-C) 5.7 GHz 0.95 cm X-band (NLC/GLC) 11.4 GHz 0.42 cm (CLIC) 25-30 GHz 0.2 cm Accelerating structure size is dictated by wavelength of the rf accelerating wave. Wakefields related to structure size; thus so is the difficulty in controlling emittance growth and final luminosity. Bunch spacing, train length related to rf frequency Damping ring design depends on bunch length, hence frequency RF Bands Frequency dictates many of the design issues for LC 9-Nov-05 LAL Orsay Seminar

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 9-Nov-05 LAL Orsay Seminar

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 9-Nov-05 LAL Orsay Seminar

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 9-Nov-05 LAL Orsay Seminar

The Key Decisions Critical choices: luminosity parameters & gradient 9-Nov-05 LAL Orsay Seminar

Making Choices – The Tradeoffs Many decisions are interrelated and require input from several WG/GG groups 9-Nov-05 LAL Orsay Seminar

Superconducting RF Cavities High Gradient Accelerator 35 MV/meter -- 40 km linear collider 9-Nov-05 LAL Orsay Seminar

Improved Cavity Shapes 9-Nov-05 LAL Orsay Seminar

Improved Fabrication 9-Nov-05 LAL Orsay Seminar

Improved Processing Electropolishing Chemical Polish Electro Polish 9-Nov-05 LAL Orsay Seminar

(Improve surface quality -- pioneering work done at KEK) 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 9-Nov-05 LAL Orsay Seminar

Gradient Results from KEK-DESY collaboration must reduce spread (need more statistics) single-cell measurements (in nine-cell cavities) 9-Nov-05 LAL Orsay Seminar

Baseline Gradient 9-Nov-05 LAL Orsay Seminar

Large Grain Single Crystal Nb Material 9-Nov-05 LAL Orsay Seminar

ILC Siting and Conventional Facilities 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 and Europe are to determine sample sites by the end of 2005 9-Nov-05 LAL Orsay Seminar

1 vs 2 Tunnels Tunnel must contain Save maybe $0.5B Issues Linac Cryomodule RF system Damping Ring Lines Save maybe $0.5B Issues Maintenance Safety Duty Cycle 9-Nov-05 LAL Orsay Seminar

Possible Tunnel Configurations One tunnel of two, with variants ?? 9-Nov-05 LAL Orsay Seminar

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 9-Nov-05 LAL Orsay Seminar

Beam Detector Interface Tauchi LCWS05 9-Nov-05 LAL Orsay Seminar

ACFA Joint Linear Collider Physics and Detector Working Group “Our task is to continue studies on physics at the linear collider more precisely and more profoundly, taking into account progresses in our field, as well as on developments of detector technologies best suited for the linear collider experiment. As we know from past experiences, this will be enormously important to realize the linear collider.” Akiya Miyamoto 9-Nov-05 LAL Orsay Seminar

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. 9-Nov-05 LAL Orsay Seminar

Test Facility at KEK 9-Nov-05 LAL Orsay Seminar

Test Facility at SLAC 9-Nov-05 LAL Orsay Seminar

TESLA Test Facility Linac - DESY laser driven electron gun photon beam diagnostics undulator bunch compressor superconducting accelerator modules pre-accelerator e- beam diagnostics 240 MeV 120 MeV 16 MeV 4 MeV 9-Nov-05 LAL Orsay Seminar

Fermilab ILC SCRF Program 9-Nov-05 LAL Orsay Seminar

Internationl Linear Collider Timeline 2005 2006 2007 2008 2009 2010 Global Design Effort Project Baseline configuration Reference Design Technical Design ILC R&D Program Expression of Interest to Host International Mgmt

Conclusions We have determined a number of very fundamental physics questions to answer, like …. What determines mass? What is the dark matter? Are there new symmetries in nature? What explains the baryon asymmetry? Are the forces of nature unified We are developing the tools to answer these questions and discover new ones Neutrino Physics Large Hadron Collider International Linear Collider The next era of particle physics will be very exciting 9-Nov-05 LAL Orsay Seminar