Opportunities at the International Linear Collider ILC Columbium
Opportunities at the International Linear Collider (ILC) Columbium or is it Niobium US or Europe? ILC in Japan? Nigel Lockyer, University of Pennsylvania Ettore Majorana, Erice, Sicily, September 3, 2006
Particle Physics Progress 21 th Century Physicists want a grand View of the landscape Are We Close to the Top? String theorist Burt Ovrut hanging from a rope
The Progress – Standard model of particle physics is a triumph of 20 th century physics – Standard Electroweak model describes all measurements to O(0. 1%) – MUST add pure EWK radiative corrections sensitive to mass of the top quark in order for results to be consistent – Standard Model is a gauge theory massless particles – Electroweak symmetry breaking gives mass to W, Z, quarks and leptons – The EW precision measurements (LEP/SLC+Tevatron) favor a fundamental scalar at low mass (HIGGS) – Unstable quantum corrections to Higgs mass tells us new physics at energy scales of O(1 Te. V) needed to stabilize Higgs mass…. Goal: Explore Te. V Energy Range
Precision Electroweak Tests of SM Many of the uncertainties at the level of one part per thousand Z mass 2, 000 th of 1%! Z-line shape Invisible Width N = 2. 9841 0. 0083 Number of light neutrino species:
• • A Successful Pattern of Hadron Colliders UA 1 and. Complementing UA 2 discovered the W and Z bosons at a hadron collider e+e. Colliders LEP approved before Z discovered LEP/SLC moved Particle Physics well beyond UA 1/UA 2 Discovery • LEP searches and precision measurements eliminated many models eg. Leptoquarks • 3 families of neutrinos • Minimal SUSY (MSSM) still consistent with all the data, hence it is still the most possible extension of the standard model Top Discovery at Tevatron (CDF & D 0) • We have “great confidence” that a Higgs exists or something that performs that function at the Te. V scale “Higgs must exist” Susskind, Erice 2006
Motivating Questions 1. Are there undiscovered new symmetries or laws in nature? 2. Are there extra dimensions of space? 3. Do all the forces become one? 4. How can we solve the mystery of Dark Energy? 5. What is Dark Matter? 6. What happened to the anti-matter?
Evolution of Accelerators 9 km/13 cm = 69, 231 14 Te. V/80 ke. V = 175, 000 Technology of accelerators has made huge gains
Discovery of the Century at LHC? ILC will help dig down and uncover deeper picture
International Linear Collider
International Linear Collider: Performance Specification (White Paper) – Initial maximum energy of 500 Ge. V, operable over the range 200 -500 Ge. V for physics running. – Equivalent (scaled by 500 Ge. V/ s) integrated luminosity for the first four years after commissioning of 500 fb-1. – Ability to perform energy scans with minimal changeover times. – Beam energy stability and precision of 0. 1%. – Capability of 80% electron beam polarization over the range 200 -500 Ge. V. – Two interaction regions, at least one of which allows for a crossing angle enabling gg collisions. – Ability to operate at 90 Ge. V for calibration running. – Machine upgradeable to approximately 1 Te. V.
Key Points for Why We Want the ILC Precision Higgs Factory • Measurements are a window to new physics • New physics is expected at the Te. V scale Synergy with LHC Discoveries • Discoveries lead to questions such as: – Standard model Higgs? Measure couplings, spin, parity – Is that supersymmetry? Measure spin and quantum nos. – Is that neutralino “dark matter” Measure mass to 1% – How many extra dimensions are there? LHC+ILC best
Higgs at ILC • Little Higgs Model Quadratic divergence of the Higgs boson mass can be cancelled by extra fermions and bosons about 1 Te. V. Higgs Self Coupling etc. . • Higgs-less Model A new model based on 5 dim space -time. The unitarity of the WW scattering is saved by the Kaluza-Klein modes of the gauge bosons. • Crucial information on Higgs potential • Self coupling to 10%(Yamashita) 4 b-jets 80% efficiency 2 years running etc. .
ILC has Powerful Recoil Technique In e+ e- Z + anything (even invisible decay products) the recoil mass of system is determined by kinematics and conservation of energy. Peak in recoil mass corresponds to Higgs Sensitive to invisible Higgs decay
Measuring the Higgs Spin and Parity Miller et al. Scan h. Z production near threshold Can unambiguously show that JP=0+ 20 fb-1 per point Difficult to do at LHC
Powerful Test at ILC e+ l+ Z At ILC : (6% of Z decays) e- Z* l. H The absolute cross section of e+ e- Z* Zh involves vertex that gives Z its mass. Sum rule tests whether observed h 0 generates all mass of the Z boson. LHC measures ratios of couplings and cannot determine the ZZh coupling directly. If the production rate is smaller, then multiple h 0 bosons must be contributing to Z mass.
Higgs Branching Ratios Measure Higgs decay branching ratios by measuring system that recoils against Z This level of precision only possible at ILC qualitatively different from LHC (Hinchliffe)
Perform accurate & Model Independent measurements of the Higgs Couplings Look for deviation from straight line SUSY and Extra Dimension Models can behave differently The strength of the Higgs couplings to fermions and bosons is given by the mass of the particle Critical Test f ~ mf Higgs Small uncertainties f Important to detect cleanly all quarks From Joanne Hewitt
Precision SUSY at ILC • ILC has a central role to play in SUSY • SUSY observables at ILC qualitatively beyond LHC (Peskin) • Super particles could be heavy but lightest chargino should be seen at 500 Ge. V ILC (proposed initial energy). • All charginos and neutralinos should be seen at a 1 Te. V ILC • Definitive determination of spin and quantum numbers • Mass of lightest super symmetric particle to 1% (LHC 10%) • Precision mass measurements of super particles • Measure chargino and neutralino mixing (higgsino and gaugino) • If neutralino is lightest super particle and R-parity conserved then it is stable and a dark matter candidate • Only ILC provides accurate enough input for dark matter relic abundance calculations which seem to get in ball park of WMAP allowed range
New Gauge Bosons Riemann Indirect sensitivity beyond LHC even at 500 Ge. V Measure Z΄ couplings given mass from LHC
ITRP (Wise Cold People) (International Technology Recommendation Panel) “This recommendation is made with the understanding that we are recommending a technology, not a design. ” August 20 th, 2004 Super conducting RF is accelerating technology choice (Global all aboard!)
ILC Design Needed Good Start
GDE RDR / R&D Organization FALC ICFA FALC Resource Board ILCSC GDE Directorate GDE Executive Committee GDE R & D Board GDE Change Control Board Global R&D Program GDE Design Cost Board RDR Design Matrix
Baseline Reference Design Report July Jan Frascati Bangalore Vancouver Dec 2006 Valencia Freeze Configuration Organize for RDR Review Design/Cost Methodology Review Initial Design / Cost Design and Costing Review Final Design / Cost RDR Document Preliminary RDR Released
The ILC Baseline Machine ~31 km 20 mr RTML ~1. 6 km R = 955 m E = 5 Ge. V ML ~10 km (G = 31. 5 MV/m) BDS 5 km 2 mr e+ undulator @ 150 Ge. V (~1. 2 km) not to scale x 2
Baseline Electron Source • DC Guns incorporating photocathode illuminated by a Ti: Sapphire drive laser. • Long electron microbunches (~2 ns) are bunched in a bunching section • Accelerated in a room temperature linac to about 100 Me. V and SRF linac to 5 Ge. V. laser E=70 -100 Me. V Positron-style roomstandard ILC temperature SCRF modules accelerating section sub-harmonic bunchers + solenoids diagnostics section
Baseline Positron Source • Helical Undulator Based Positron Source with Keep Alive System – The undulator source will be placed at the 150 Ge. V Primary e source point in main electron linac. - • This will allow constant charge operation across the foreseen centre-of-mass energy operating range. Beam Delivery System e. DR 150 Ge. V 100 Ge. V Helical Undulator In By-Pass Line Auxiliary Source Photon Collimators Positron Linac IP 250 Ge. V e+ DR Target e. Dump Photon Beam Dump e- Photon Target Adiabatic Matching Device e+ preaccelerator ~5 Ge. V
Baseline ILC Cryomodule • The baseline ILC Cryomodule will have 8 9 -Cell cavities per cryomodule. The quadrupole will be at the center in the baseline design. • Every 4 th cryomodule in the linac would include a quadrupole with a corrector and BPM package.
Main Linac: Baseline RF Unit
ILC Damping Ring: Baseline Design • Positrons: Two rings of ~ 6 km circumference in a single tunnel. • Two rings are needed to reduce e-cloud effects unless significant progress can be made with mitigation techniques. • Preferred to 17 km due to: –Space-charge effects –Acceptance –Tunnel layout (commissioning time, stray fields) • Electrons: one 6 km ring. • Preferred to 3 km due to: –Larger gaps between mini-trains for clearing ions. –Injection and extraction kickers ‘low risk’
RF Power: Baseline Klystrons Specification: 10 MW MBK 1. 5 ms pulse 65% efficiency Thales CPI Toshiba ILC (XFEL @ DESY) has a very limited experience with these Klystrons. Production and operation of these Klystron are issues that needs to be addressed.
Beam Delivery System (BDS) • Baseline (supported, at the moment, by GDE exec) – two BDSs, 20/2 mrad, 2 detectors, 2 longitudinally separated IR halls • Alternative 1 – two BDSs, 20/2 mrad, 2 detectors in single IR hall @ Z=0 • Alternative 2 – single IR/BDS, collider hall long enough for two push-pull detectors
Site power: 140 MW (500 Ge. V baseline) Main Linacs 97 MW Sub-Systems 43 MW RF: 76 MW Injectors 78% Cryogenics: Damping rings 21 MW BDS Auxiliaries 65% 60% Beam 22. 6 MW
ILC is a Truly Global Project • Project initiated by three regions of world • Design performed in all three regions of world • R&D is all three regions • Test Facilities in all three regions • Accelerator Physicists Work Well Together • Decision on site will be global, as was technology decision • US will bid to Host (DOE working towards this goal)
Main ILC R&D Issue Produce high gradient cavities reliably
SRF Cavity Gradient Cavity type initial upgrade Qualified gradient Operational gradient Length* energy MV/m Km Ge. V TESLA 35 31. 5 10. 6 250 LL 40 36. 0 +9. 3 500 * assuming 75% fill factor Total length of one 500 Ge. V linac 20 km
Cavities for Module 6 @ DESY 35 35 36 32 34
Vertical Test Results @ DESY, 9 cavities
ILC Main Linac Accelerator R&D Goals • The ILC-Global Design Effort (GDE)’s priorities as being discussed by the S 0, S 1 and S 2 Task Forces. Still being defined…present stage the goals being discussed are: – Develop cavity processing parameters for a reproducible cavity gradient of 35 MV/m; improve the yield of 9 -cell cavities for gradient of 35 MV/m in vertical tests (S 0). Carry out parallel/coupled R&D on cavity processing, fabrication and materials to identify paths to success. – Assemble and test one or more cryomodules with average gradient > 31. 5 MV/m (S 1). – Build and test one or more ILC rf units at ILC beam parameters, high gradient, and full pulse rep rate (S 2. 1) – To develop plans for an ILC Main Linac System Test consisting of several rf units (S 2. 2). To achieve the goals, R&D plan will also strengthen the technical capabilities and infrastructure of collaborating institutions.
Global Plan Emerging Back to Basics
New Shapes Breakthrough 50 MV/m in Single Cells ! Lower Surface Magnetic Field & Lower Losses Need Multi-cells Next Reentrant Cornell KEK Low Loss Jlab KEK Tesla Shape
Higher Gradient in Single Cell: Eacc = 47 - 52 MV/m Fabricated at Cornell Ichiro @ KEK
ILC Cavity Material Grain size R&D • • The single cell and/or large grain Niobium shows considerable promise in achieving higher gradient. R&D activities are under way at KEK, Jlab and DESY usingle cell cavities. It could eliminate the need to electropolish Two 9 -cell cavities are being fabricated. Ningxia Heraeus
US: ILC Cavity R&D • In order to make timely progress on the ILC cavities gradient goal Fermilab has taken the approach that – Maximizes the utilization of existing U. S. SRF infrastructure – While developing Fermilab based expertise and infrastructure. 60 Cavities (by FY 07) ACCEL AES
R&D Around the World Three Regions-only look at DESY, KEK, US
Japan ATF/ATF 2
KEK: Main Linac SRF Unit R&D Goal: Achieve Higher Gradient >40 MV/m in a new Cavity Design Parallel Fermilab but emphasis on high gradient
DESY String Assembly The assembly of a string of 8 cavities into a string. Class 100 clean room Facilities being setup at Fermilab as part of SMTF. The inter-cavity connection is done in class 10 cleanroom
INFN/DESY Co-Axial Tuner Lorentz Force Detuning Micro-phonics Successfully operated with superstructures Piezo-tuner integration still pending
DESY Module Assembly The module assembly is well defined and about 10 modules have been made of several designs ILC will need about 4000 modules.
Cryomodules at DESY TTF European Activities Centered Around DESY Lab in Germany
Fermilab: A Possible Host of ILC A Truly International Laboratory will be necessary
ILC 1. 3 GHz Cavities @ FNAL Bead pull RF Testing @ FNAL Joint ANL/FNAL BCP/EP Facility 4 cavities received from ACCEL 4 cavities on order at AES 4 cavities expected from KEK • • Industrial fabrication of cavities. BCP and vertical testing at Cornell (25 MV/m) EP and vertical testing at TJNL. ( 35 MV/m) Joint BCP/EP facility being developed ANL (late 06) High Power Horizontal test facility @ FNAL (ILCTA-MDB) Vertical test facility under development @ FNAL ( IB 1) Single/large Crystal cavity development with TJNL
Vertical Test of ACCEL Cavity 60 mm BCP (nominal) + 50 mm at ACCEL Low Field: Q >5 x 1010, Eacc = 26 MV/m Q Eacc (Mv/m)
Fermilab ILC Infrastructure Eddy Current Scanner RF Measurement and Tuning LLRF Cryomodule Assembly @ MP 9 ILCTA @ Fermilab Cavity String Assembly Clean Room Class 10/100 Fermilab Photo-injector
Horizontal and Vertical Test Stands Single Cavity Horizontal Test Stand Multiple Cavities Vertical Test Stand • Improved Design compared to DESY • Fermilab had designed VTS for DESY • Bid Package is out • We are in process of designing a new VTS to be installed at IB 1. • Plan to install and commission at Meson in summer 06. • It is expected to be operational in CY 06.
Cryomodule Design & Fabrication • In FY 05 Fermilab started on converting the DESY/INFN design of the ILC cryomodule (Type-III+). • Fermilab is part of a group that is working towards a design of an ILC cryomodule. • The Goal is to design an improved ILC cryomodule (Type-IV) and build one at Fermilab by FY 08. High Power testing of the cavities and the fabrication of 1 st US cryomodule with new design 2008.
ILCTA @ Fermilab Phase 1: 1 RF Unit Goal: Address S 1 and S 2 issues. Photo-injector Phase B Fermilab Diagnostics Dump 40 Me. V ebeam SLAC Components provided by US and International Collaborators 1 st RF Unit Integrated by US Laboratories and Universities 2 nd RF Unit Produced and Integrated by ILC laboratories, Universities and Industries ILC LLRF, Control, Instrumentation, Feedback etc. ILC Institutions
Jlab: Electro-polish Development for ILC Jlab EP Cabinet This facility has been commissioned. HPR and Assembly Alignment Cage 9 -Cell TESLA Shape cavity result soon
ILC Industrialization • The principle goal industrialization activities is: • Establish industrial the capability and infrastructure to manufacture the components that must be mass produced SCRF Cavities: • ~20, 000 cavities required for 500 Ge. V of linac • Reliably achieve > 35 MV/m and Q ~1 x 1010 Cryomodule design that can be mass produced • ~2000 required/500 Ge. V of linac RF systems • ~ 600 klystrons ( 1. 3 GHz, 10 MW, 1. 5 ms, 5 Hz) • ~ 600 modulators • Waveguide, circulators, host of other RF and vacuum components… Large Cryogenic systems (~ 40 KW at 1. 8 K) Detectors, instrumentation, etc… Civil construction • Industrial studies aimed at cost reduction in all three regions
Summary • Precision measurements at the ILC necessary for us to understand phenomena at Te. V Scale – Higgs + new physics (Little Higgs, SUSY, Extra Dimensions…… • ILC is powerful instrument (polarization, initial energy known, energy scan • Organization (Global Design Effort) established • Timeline RDR 2006 (end) TDR 2009 • R&D high priority worldwide • Prepare to propose ILC
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