The International Linear Collider Barry Barish ANL Colloquium
The International Linear Collider Barry Barish ANL Colloquium 3 -Jan-06 ANL Director's Colloquium
Particle Physics Inquiry Based Science 1. Are there undiscovered principles of nature: New symmetries, new physical laws? 2. 3. 4. 5. 6. 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? 7. What are neutrinos telling us? 8. How did the universe come to be? 9. What happened to the antimatter? 3 -Jan-06 from the Quantum Universe 2 ANL Director's Colloquium
Answering the Questions Three Complementary Probes • Neutrinos as a Probe – Particle physics and astrophysics using a weakly interacting probe • High Energy Proton Colliders – Opening up a new energy frontier ( ~ 1 Te. V scale) • High Energy Electron Positron Colliders – Precision Physics at the new energy frontier 3 -Jan-06 ANL Director's Colloquium 3
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? 3 -Jan-06 ANL Director's Colloquium 4
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 3 -Jan-06 ANL Director's Colloquium 5
Why a Te. V 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 Te. V ILC and the LHC science. 3 -Jan-06 ANL Director's Colloquium 6
Electroweak Precision Measurements What causes mass? ? The mechanism – Higgs or alternative appears around the corner 3 -Jan-06 ANL Director's Colloquium 7
Accelerators and the Energy Frontier Large Hadron Collider CERN – Geneva Switzerland 3 -Jan-06 ANL Director's Colloquium 8
LHC and the Energy Frontier Source of Particle Mass Discover the Higgs The Higgs Field LEP fb-1 FNAL or variants or ? ? ? 3 -Jan-06 ANL Director's Colloquium 9
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 3 -Jan-06 ANL Director's Colloquium 10
This led to higher energy machines: Electron-Positron Colliders ADA Bruno Touschek built the first successful electron-positron collider at Frascati, Italy (1960) Eventually, went up to 3 Ge. V 3 -Jan-06 ANL Director's Colloquium 11
But, not quite high enough energy …. 3. 1 Ge. V and SPEAR at SLAC 3 -Jan-06 ANL Director's Colloquium Burt Richter Nobel Prize Discovery Of Charm Particles 12
The rich history for e+e- continued as higher energies were achieved … DESY PETRA Collider 3 -Jan-06 ANL Director's Colloquium 13
Electron Positron Colliders The Energy Frontier 3 -Jan-06 ANL Director's Colloquium 14
Why e+e- Collisions ? • elementary particles • well-defined – energy, – angular momentum • uses full COM energy • produces particles democratically • can mostly fully reconstruct events 3 -Jan-06 ANL Director's Colloquium 15
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 3 -Jan-06 ANL Director's Colloquium 16
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 3 -Jan-06 ANL Director's Colloquium 17
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. 3 -Jan-06 ANL Director's Colloquium 18
Is There a New Symmetry in Nature? Supersymmetry Bosons Fermions Virtues of Supersymmetry: – Unification of Forces – The Hierarchy Problem – Dark Matter … 3 -Jan-06 ANL Director's Colloquium 19
Parameters for the ILC • Ecm adjustable from 200 – 500 Ge. V • Luminosity ∫Ldt = 500 fb-1 in 4 years • Ability to scan between 200 and 500 Ge. V • Energy stability and precision below 0. 1% • Electron polarization of at least 80% • The machine must be upgradeable to 1 Te. V 3 -Jan-06 ANL Director's Colloquium 20
A Te. V 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. 3 -Jan-06 ANL Director's Colloquium 21
GLC GLC/NLC Concept • 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. 3 -Jan-06 ANL Director's Colloquium 22
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. 3 -Jan-06 ANL Director's Colloquium 23
Drive Beam CLIC Concept Main Accelerator The main linac rf power is produced by decelerating a highcurrent (150 A) lowenergy (2. 1 Ge. V) drive beam Nominal accelerating gradient of 150 MV/m GOAL Proof of concept ~2010 3 -Jan-06 ANL Director's Colloquium 24
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 3 -Jan-06 ANL Director's Colloquium 25
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). 3 -Jan-06 ANL Director's Colloquium 26
The Community Self-Organized Nov 13 -15, 2004 3 -Jan-06 ANL Director's Colloquium 27
Global Design Effort (GDE) • • February 2005, at TRIUMF, ILCSC and ICFA unanimously endorsed the search committee choice for GDE Director On March 18, 2005 Barry Barish officially accepted the position at the opening of LCWS 05 meeting at Stanford 3 -Jan-06 ANL Director's Colloquium 28
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. ) 3 -Jan-06 ANL Director's Colloquium 29
The GDE Plan and Schedule 2005 2006 2007 2008 2009 2010 CLIC Global Design Effort Baseline configuration Reference Design Project LHC Physics Technical Design ILC R&D Program Expression of Interest to Host International Mgmt 3 -Jan-06 ANL Director's Colloquium
GDE Begins at Snowmass 670 Scientists attended two week workshop at Snowmass 3 -Jan-06 GDE Members Americas 22 Europe 24 Asia 16 ANL Director's Colloquium 31
Designing a Linear Collider Superconducting RF Main Linac 3 -Jan-06 ANL Director's Colloquium 32
GDE Organization for Snowmass • • • Provide input Global Group • • • WG 1 LET bdyn. WG 2 Main Linac WG 3 a Sources WG 3 b DR WG 4 BDS WG 5 Cavity Technical sub-system Working Groups GG 1 Parameters GG 2 Instrumentation GG 3 Operations & Reliability GG 4 Cost & Engineering GG 5 Conventional Facilities GG 6 Physics Options 3 -Jan-06 ANL Director's Colloquium 33
Specific Machine Realizations rf bands: RF Bands 1. 3 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 25 -30 GHz 0. 2 cm (CLIC) GHz l = L-band (TESLA) 3. 7 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. Ø Bunch spacing, train length related to rf frequency Ø Damping ring design depends on bunch length, hence frequency Frequency dictates many of the design issues for LC 3 -Jan-06 ANL Director's Colloquium 34
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 3 -Jan-06 ANL Director's Colloquium 35
The Key Decisions Critical choices: luminosity parameters & gradient 3 -Jan-06 ANL Director's Colloquium 36
Making Choices – The Tradeoffs Many decisions are interrelated and require input from several WG/GG groups 3 -Jan-06 ANL Director's Colloquium 37
ILC Baseline Configuration • Configuration for 500 Ge. V machine with expandability to 1 Te. V • Some details – locations of low energy acceleration; crossing angles are not indicated in this cartoon. 3 -Jan-06 ANL Director's Colloquium 38
Cost Breakdown by Subsystem Civil SCRF Linac 3 -Jan-06 ANL Director's Colloquium 39
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 3 -Jan-06 ANL Director's Colloquium 40
TESLA Cavity ~1 m 9 -cell 1. 3 GHz Niobium Cavity Reference design: has not been modified in 10 years 3 -Jan-06 ANL Director's Colloquium 41
How Costs Scale with Gradient? 35 MV/m is close to optimum Relative Cost Japanese are still pushing for 4045 MV/m 30 MV/m would give safety margin C. Adolphsen (SLAC) 3 -Jan-06 Gradient MV/m ANL Director's Colloquium 42
Superconducting RF Cavities High Gradient Accelerator 35 MV/meter -- 40 km linear collider 3 -Jan-06 ANL Director's Colloquium 43
Improved Cavity Shapes 3 -Jan-06 ANL Director's Colloquium 44
Improved Fabrication 3 -Jan-06 ANL Director's Colloquium 45
Improved Processing Electropolishing Chemical Polish Electro Polish 3 -Jan-06 ANL Director's Colloquium 46
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 3 -Jan-06 ANL Director's Colloquium 47
single-cell measurements (in nine-cell cavities) Gradient Results from KEK-DESY collaboration must reduce spread (need more statistics) 3 -Jan-06 ANL Director's Colloquium 48
Baseline Gradient 3 -Jan-06 ANL Director's Colloquium 49
Large Grain Single Crystal Nb Material 3 -Jan-06 ANL Director's Colloquium 50
The Main Linac Configuration • Klystron – 10 MW (alternative sheet beam klystron) • RF Configuration – 3 Cryomodules, each with 8 cavities • Quads – one every 24 cavities is enough 3 -Jan-06 ANL Director's Colloquium 51
Other Features of the Baseline • Electron Source – Conventional Source using a DC gun 3 -Jan-06 ANL Director's Colloquium 52
Other Features of the Baseline • Positron Source – Helical Undulator with Polarized beams Primary esource Beam Delivery System e. DR 150 Ge. V 100 Ge. V Helical Undulator In By-Pass Line Photon Collimators Auxiliary e. Source 3 -Jan-06 Positron Linac IP 250 Ge. V e+ DR Target e. Dump Photon Beam Dump Photon Target Adiabatic Matching Device ANL Director's Colloquium e+ preaccelerator ~5 Ge. V 53
Damping Ring Options 3 or 6 km rings can be built in independent tunnels “dogbone” straight sections share linac tunnel 3 Km 3 -Jan-06 Two or more rings can be stacked in a single tunnel ANL Director's Colloquium 6 Km 54
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 3 -Jan-06 ANL Director's Colloquium 55
1 vs 2 Tunnels • Tunnel must contain – Linac Cryomodule – RF system – Damping Ring Lines • Save maybe $0. 5 B • Issues – Maintenance – Safety – Duty Cycle 3 -Jan-06 ANL Director's Colloquium 56
Possible Tunnel Configurations • 3 -Jan-06 One tunnel of two, with variants ? ? ANL Director's Colloquium 57
Americas Sample Site • Design to “sample sites” from each region – Americas – near Fermilab – Japan – Europe – CERN & DESY • Illinois Site – depth 135 m – Glacially derived deposits overlaying Bedrock. The concerned rock layers are from top to bottom the Silurian dolomite, Maquoketa dolomitic shale, and the Galena. Platteville dolomites. 3 -Jan-06 ANL Director's Colloquium 58
Parametric Approach • A working space - optimize machine for cost/performance 3 -Jan-06 ANL Director's Colloquium 59
Beam Detector Interface Tauchi LCWS 05 3 -Jan-06 ANL Director's Colloquium 60
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 3 -Jan-06 ANL Director's Colloquium 61
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. 3 -Jan-06 ANL Director's Colloquium 62
Test Facility at KEK 3 -Jan-06 ANL Director's Colloquium 63
Test Facility at SLAC 3 -Jan-06 ANL Director's Colloquium 64
TESLA Test Facility Linac - DESY e- beam diagnostics undulator photon beam diagnostics 240 Me. V 3 -Jan-06 bunch compressor superconducting accelerator modules 120 Me. V ANL Director's Colloquium e- beam diagnostics laser driven electron gun preaccelerator 16 Me. V 4 Me. V 65
Fermilab ILC SCRF Program 3 -Jan-06 ANL Director's Colloquium 66
International 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 3 -Jan-06 ANL Director's Colloquium
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 3 -Jan-06 ANL Director's Colloquium 68
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