The Next Great Particle Accelerator A TeV Scale l +l _ Linear Collider
Barry Barish Caltech JLab Colloquium 11-Sept-08 Particle Physics An Inquiry Based Science
1. Are there undiscovered principles of nature: New symmetries, new physical laws? 2. How can we solve the mystery of dark energy? 3. Are there extra dimensions of space? 4. Do all the forces become one? 5. Why are there so many kinds of particles? 6. 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? from the Quantum Universe 11-Sept-08 The International Linear Collider 2 JLab Colloquium 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
• Increasing connections to Astrophysics/Cosmology
11-Sept-08 The International Linear Collider 3 JLab Colloquium Exploring the Terascale the tools • The LHC – It will lead the way and has large reach – Quark-quark, quark-gluon and gluon-gluon collisions at 0.5 - 5 TeV – Broadband initial state • The ILC – A second view with high precision – Electron-positron collisions with fixed energies, adjustable between 0.1 and 1.0 TeV – Well defined initial state • Together, these are our tools for the terascale
11-Sept-08 The International Linear Collider 4 JLab Colloquium Electron-Positron Colliders
Bruno Touschek built the first ADA successful electron-positron collider at Frascati, Italy (1960)
Eventually, went up to 3 GeV
11-Sept-08 The International Linear Collider 5 JLab Colloquium But, not quite high enough energy ….
3.1 GeV
Burt Richter Nobel Prize and
Discovery Of SPEAR at SLAC Charm Particles
11-Sept-08 The International Linear Collider 6 JLab Colloquium The rich history for e+e- continued as higher energies were achieved …
DESY PETRA Collider
11-Sept-08 The International Linear Collider 7 JLab Colloquium And also at LEP, where the stage has been set for the terascale Winter 2003 What causes mass ?? 6 theory uncertainty (5) The mechanism – Higgs had = 0.02761 0.00036 or alternative appears 0.02747 0.00012 around the corner 4 Without NuTeV
2
Excluded Preliminary 0 20 100 400
mH GeV
11-Sept-08 The International Linear Collider 8 JLab Colloquium Three Generations of e+e- Colliders The Energy Frontier
ILC LEP
PETRA Fourth
Generation? ENERGY SPEAR
1970 YEAR 2020
11-Sept-08 The International Linear Collider 9 JLab Colloquium Possible TeV Scale Lepton Colliders
ILC < 1 TeV Technically possible ILC ~ 2020 +
QUAD Drive beam - 95 A, 300 ns QUAD POWER EXTRACTION from 2.4 GeV to 240 MeV STRUCTURE CLIC CLIC < 3 TeV ACCELERATING STRUCTURES Feasibility? Main beam – 1 A, 200 ns from 9 GeV to 1.5 TeV BPM Longer timescale Muon Collider Much R&D Needed Muon Collider • Neutrino Factory R&D + < 4 TeV • bunch merging • much more cooling FEASIBILITY?? • etc Much longer timescale 11-Sept-08 The International Linear Collider 10 JLab Colloquium Why e+e- Collisions ?
• elementary particles • well-defined – energy, – angular momentum • uses full COM energy • produces particles democratically • can mostly fully reconstruct events
11-Sept-08 The International Linear Collider 11 JLab Colloquium LHC: Low mass Higgs: H gg 2 MH < 150 GeV/c . Rare decay channel: BR ~ 10-3
. Requires excellent electromagnetic calorimeter performance . acceptance, energy and angle resolution, . g/jet and g/p0 separation
. Motivation for LAr/PbWO4 calorimeters for CMS
. Resolution at 100 GeV: 1 GeV
. Background large: S/B 1:20, but can estimate from non signal areas
CMS
11-Sept-08 The International Linear Collider 12 JLab Colloquium ILC: Precision Higgs physics
. Model-independent Studies • mass • absolute branching ratios • total width • spin • top Yukawa coupling • self coupling . Precision Measurements Garcia-Abia et al
11-Sept-08 The International Linear Collider 13 JLab Colloquium 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
11-Sept-08 The International Linear Collider 14 JLab Colloquium What can we learn from the Higgs? Precision measurements of Higgs coupling
Higgs Coupling strength is proportional to Mass
11-Sept-08 The International Linear Collider 15 JLab Colloquium e+e- : Studying the Higgs determine the underlying model
SM 2HDM/MSSM
Yamashita et al Zivkovic et al
11-Sept-08 The International Linear Collider 16 JLab Colloquium Top Quark Measurements
Threshold scan provides mass measurement
Theory (NNLL) controls mt(MS) to 100 MeV
11-Sept-08 The International Linear Collider 17 JLab Colloquium Top Quark Measurements
Bounds on axial ttbarZ and left handed tbW for LHC and ILC compared to deviations in various models
11-Sept-08 The International Linear Collider 18 JLab Colloquium Supersymmetry
Supersymmetric Partner ~ u c t H u~ c~ t~ H~ ~ ~ ~ ~ d s b g H d s b g H~ ~ ~ ~ ~ e W e W ~ e Z e~ ~ ~ Z
Spin Spin Spin Spin Spin Spin 1/2 1 0 0 1/2 1/2
11-Sept-08 The International Linear Collider 19 JLab Colloquium Supersymmetry at ILC e+e- production crosssections - Measure quantum numbers - Is it MSSM, NMSSM, …? - How is it broken?
ILC can answer these questions! - tunable energy - polarized beams
11-Sept-08 The International Linear Collider 20 JLab Colloquium ILC Supersymmetry Two methods to obtain absolute sparticle masses: Kinematic Threshold: In the continuum
Freitas
Martyn
Determine SUSY Minimum and maximum determines parameters without model masses of primary slepton and assumptions secondary neutralino/chargino
11-Sept-08 The International Linear Collider 21 JLab Colloquium Supersymmetry quark and lepton unification
Do Quarks and Leptons also Unify?
1015 TeV •Predicted in most models •Can be tested at the ILC
11-Sept-08 The International Linear Collider 22 JLab Colloquium 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.
11-Sept-08 The International Linear Collider 23 JLab Colloquium Why Linear?
• Circular Machine R Synchrotron – E ~ (E4 /m4 R) R Radiation – Cost ~ a R + b E m,E ~ a R + b (E4 /m4 R) – Optimization : R ~ E2 Cost ~ c E2
Circular – Cost (linear) ~ a L Collider Linear Collider – where L ~ E
cost ~ 200 GeV Energy
11-Sept-08 The International Linear Collider 24 JLab Colloquium How the physics defines the ILC
11-Sept-08 The International Linear Collider 25 JLab Colloquium 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
11-Sept-08 The International Linear Collider 26 JLab Colloquium ILC – Underlying Technology
• Room temperature copper structures
OR
• Superconducting RF cavities
11-Sept-08 The International Linear Collider 27 JLab Colloquium 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
11-Sept-08 The International Linear Collider 28 JLab Colloquium Superconducting RF Technology
• Forward looking technology for the next generation of particle accelerators: particle physics; nuclear physics; materials; medicine
• The ILC R&D is leading the way Superconducting RF technology – high gradients; low noise; precision optics
11-Sept-08 The International Linear Collider 29 JLab Colloquium Designing a Linear Collider pre-accelerator few GeV source KeV damping extraction ring few GeV 250-500 GeV & dump few GeV final focus
IP bunch main linac compressor collimation
Superconducting RF Main Linac
11-Sept-08 The International Linear Collider 30 JLab Colloquium Luminosity & Beam Size
2 nb N frep L H D 2 x y
• frep * nb tends to be low in a linear collider
10 L frep [Hz] nb N [10 ] x [ m] y [ m] ILC 2x1034 5 3000 2 0.5 0.005 SLC 2x1030 120 1 4 1.5 0.5 LEP2 5x1031 10,000 8 30 240 4 PEP-II 1x1034 140,000 1700 6 155 4
• Achieve luminosity with spot size and bunch charge
11-Sept-08 The International Linear Collider 31 JLab Colloquium Achieving High Luminosity
• Low emittance machine optics • Contain emittance growth • Squeeze the beam as small as possible
e- e+
~ 5 nm Interaction Point (IP)
11-Sept-08 The International Linear Collider 32 JLab Colloquium ILC Reference Design
– 11km SC linacs operating at 31.5 MV/m for 500 GeV – Centralized injector • Circular damping rings for electrons and positrons • Undulator-based positron source – Single IR with 14 mrad crossing angle – Dual tunnel configuration for safety and availability
Reference Design – Feb 2007
11Documented-Sept-08 in TheReference International Linear Collider Design Report 33 JLab Colloquium RDR Design Parameters
Max. Center-of-mass energy 500 GeV
Peak Luminosity ~2x1034 1/cm2s
Beam Current 9.0 mA
Repetition rate 5 Hz
Average accelerating gradient 31.5 MV/m
Beam pulse length 0.95 ms
Total Site Length 31 km
Total AC Power Consumption ~230 MW
11-Sept-08 The International Linear Collider 34 JLab Colloquium RDR Cost Estimating
• “Value” Costing System: International costing for International Project – Provides basic agreed to “value” costs – Provides estimate of “explicit” labor (man-hr)]
• Based on a call for world-wide tender: lowest reasonable price for required quality • Classes of items in cost estimate: – Site-Specific: separate estimate for each sample site – Conventional: global capability (single world est.) – High Tech: cavities, cryomodules (regional estimates)
11-Sept-08 The International Linear Collider 35 JLab Colloquium RDR Design & “Value” Costs
The reference design was “frozen” Summary as of 1-Dec-06 for the purpose of producing the RDR, including costs. RDR “Value” Costs
It is important to recognize this is a Total Value Cost (FY07) snapshot and the design will continue to evolve, due to results of 4.80 B ILC Units Shared the R&D, accelerator studies and + value engineering 1.82 B Units Site Specific The value costs have already been + reviewed three time 14.1 K person-years • 3 day “internal review” in Dec (“explicit” labor = 24.0 M person-hrs • ILCSC MAC review in Jan @ 1,700 hrs/yr) • International Cost Review (May) 1 ILC Unit = $ 1 (2007) Σ Value = 6.62 B ILC Units
11-Sept-08 The International Linear Collider 36 JLab Colloquium RDR Complete
• Reference Design Report (4 volumes)
Executive Physics Summary at the ILC
Detectors Accelerator
11-Sept-08 The International Linear Collider 37 JLab Colloquium Linear Collider Facility
Main Research Center Particle Detector
~30 km long tunnel
Two tunnels • accelerator units • other for services - RF power
11-Sept-08 The International Linear Collider 38 JLab Colloquium Conventional Facilities
72.5 km tunnels ~ 100-150 meters underground
13 major shafts > 9 meter diameter
443 K cu. m. underground excavation: caverns, alcoves, halls
92 surface “buildings”, 52.7 K sq. meters = 567 K sq-ft
11-Sept-08 The International Linear Collider 39 JLab Colloquium SCRF – The key technology Producing Cavities
Cavity Shape
Obtaining Gradient
11-Sept-08 The International Linear Collider 40 JLab Colloquium Cavity Gradient – Results
2005 2006
KEK single cell results: 2007 2005 – just learning 2006 – standard recipe 2007 – add final 3 μm fresh acid EP Note: multi-cells are harder than singles
11-Sept-08 The International Linear Collider 41 JLab Colloquium Superconducting RF Cryomodule
11-Sept-08 The International Linear Collider 42 JLab Colloquium DESY Cryomodule Performance
11-Sept-08 The International Linear Collider 43 JLab Colloquium ILC Reference Design and Plan
Making Positrons 6km Damping Ring
10MW Klystrons
Beam Delivery and Interaction Point
11-Sept-08 The International Linear Collider 44 JLab Colloquium What‟s Next? - Technical Design Phase
“Our Plan” • First Official Release
• Released in Dubna
• Next review and release: December 08
11-Sept-08 The International Linear Collider 45 JLab Colloquium Global Design Effort Essential Elements of TDP • Optimize the design for cost / performance / risk – Top down approach to „minimum‟ design; value engineering; risk mitigation
• Key Supporting R&D Program (priorities) – High Gradient R&D - globally coordinated program to demonstrate gradient for TDR by 2010 with 50%yield – Electron Cloud Mitigation – Electron Cloud tests at Cornell to establish mitigation and verify one damping ring is sufficient. – Final Beam Optics – Tests at ATF-2 at KEK
• GOAL – Bring us ready to propose a solid and defendable “construction project” to world‟s governments by 2012 (linked to LHC results)
11-Sept-08 The International Linear Collider 46 JLab Colloquium TD Phase 1
• Timescale: Interim report mid 2010
• Major theme: High-priority risk-mitigating R&D – Superconducting RF linac technology – technical demonstration of gradient, plug compatiblity and identifying potential cost reductions – Confirm mitigation of electron cloud effects – The re-baseline will take place after careful consideration and review of the results of the TD Phase 1 studies and the status of the critical R&D.
11-Sept-08 The International Linear Collider 47 JLab Colloquium Electron cloud – Goal
• Ensure the e- cloud won‟t blow up the e+ beam emittance. – Do simulations (cheap) – Test vacuum pipe coatings, grooved chambers, and clearing electrodes effect on e- cloud buildup – Do above in ILC style wigglers with low emittance beam to minimize the extrapolation to the ILC. – Tset progam underway at CESR Cornell (CesrTA)
11-Sept-08 The International Linear Collider 48 JLab Colloquium E Cloud – Results
SLAC 11-Sept-08 The International Linear Collider 49 JLab Colloquium TD Phase 2
• Timescale: Produce final reports mid-2012 – Technical Design – Project Implementation
• First goal: Technical Design – SCRF – S0 gradient and S1 Global Tests of one RF unit – Detailed technical design studies (minimum machine) – Updated VALUE estimate and schedule. – Remaining critical R&D and technology demonstration identified and planned
• Second Goal: Project Implementation Plan – Studies of governance; siting solicitation and site preparations; manufacturing; etc
11-Sept-08 The International Linear Collider 50 JLab Colloquium Detector Concepts Report
11-Sept-08 The International Linear Collider 51 JLab Colloquium Detector Performance Goals
11-Sept-08 The International Linear Collider 52 JLab Colloquium Detector Performance Goals
11-Sept-08 The International Linear Collider 53 JLab Colloquium Detector Performance Goals
• ILC detector performance requirements and comparison to the LHC detectors: ○ Inner vertex layer ~ 3-6 times closer to IP ○ Vertex pixel size ~ 30 times smaller ○ Vertex detector layer ~ 30 times thinner Impact param resolution Δd = 5 [μm] + 10 [μm] / (p[GeV] sin 3/2θ)
○ Material in the tracker ~ 30 times less ○ Track momentum resolution ~ 10 times better Momentum resolution Δp / p2 = 5 x 10-5 [GeV-1] central region Δp / p2 = 3 x 10-5 [GeV-1] forward region
○ Granularity of EM calorimeter ~ 200 times better
Jet energy resolution ΔEjet / Ejet = 0.3 /√Ejet Forward Hermeticity down to θ = 5-10 [mrad]
11-Sept-08 The International Linear Collider 54 JLab Colloquium Concept of IR hall with two detectors
The concept is evolving may be and details being accessible worked out during run
detector A
accessible during run Platform for electronic and services (~10*8*8m). Shielded detector (~0.5m of concrete) from five B sides. Moves with detector. Also provide vibration isolation.
11-Sept-08 The International Linear Collider 55 JLab Colloquium Final Reflections
• The energy frontier continues to be the primary tool to explore the central issues in particle physics
• The LHC at CERN will open the 1 TeV energy scale and we anticipate exciting new discoveries
• A companion lepton collider will be the logical next step, but such a machine has technical challenges and needs significant R&D and design now
• LHC results will inform the final design and even whether a higher energy options is needed, If so, this may also be possible, but on a longer time scale.
11-Sept-08 The International Linear Collider 56 JLab Colloquium