Opportunities at the
International Linear Collider (ILC)
Nigel Lockyer, University of Pennsylvania
Ettore Majorana, Erice, Sicily, September 3, 2006
Columbium or is it NiobiumUS or Europe?
ILC in Japan?
Particle Physics Progress 21th Century
Are We Close to the Top?
Physicists want a grand View of the landscape
String theorist Burt Ovruthanging from a rope
The Progress– Standard model of particle physics is a triumph of 20th 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 TeV) needed to stabilize Higgs mass…
.
Goal: Explore TeV Energy Range
Precision Electroweak Tests of SM
Z-line shape Invisible Width
NN = 2.9841 = 2.9841 0.0083 0.0083
Number of Number of light neutrino species:light neutrino species:
Many of the uncertainties at the level of one part per thousand
Z mass 2,000th of 1%!
A Successful Pattern of Hadron Colliders Complementing e+e- Colliders• UA1 and UA2 discovered the W and Z bosons at a hadron collider
• LEP approved before Z discovered
LEP/SLC moved Particle Physics well beyond UA1/UA2 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 & D0) • We have “great confidence” that a Higgs exists or something that
performs that function at the TeV 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
9km/13cm = 69,231 14TeV/80keV = 175,000,000
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 GeV, operable over the range 200-500 GeV for physics running.
– Equivalent (scaled by 500 GeV/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 GeV.
– Two interaction regions, at least one of which allows for a crossing angle enabling collisions.
– Ability to operate at 90 GeV for calibration running.
– Machine upgradeable to approximately 1 TeV.
Key Points for Why We Want the ILC
• New physics is expected at the TeV 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
Precision Higgs Factory
•Measurements are a window to new physics
Higgs at ILC•Little Higgs Model
Quadratic divergence of the Higgsboson mass can be cancelled by extrafermions and bosons about 1TeV.
• Higgs-less ModelA 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.
etc..
etc..
Higgs Self Coupling
•Crucial information on Higgs potential
•Self coupling to 10%(Yamashita) 4 b-jets 80% efficiency 2 years running
ILC has Powerful Recoil Technique
Peak in recoil mass corresponds to Higgs
Sensitive to invisible Higgs decay
In e+ e- Z + anything (even invisible decay products) the recoil mass of system is determined by kinematics and conservation of energy.
Measuring the Higgs Spin and Parity
Scan hZ production near threshold
20 fb-1 per point
Can unambiguously show that JP=0+
Difficult to do at LHC
Miller et al.
Powerful Test at ILC
The absolute cross section of e+ e- Z* Zh involves vertex that gives Z its mass.
Sum rule tests whether observed h0 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 h0 bosons must be contributing to Z mass.
H
Z
Z*
e-
e+ l+
l-At ILC : (6% of Z decays)
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)
~ mf
Perform accurate & Model Independent measurements of the Higgs Couplings
Higgs
Critical Test
The strength of the Higgs couplings to fermions and bosons is given by the mass of the particle
Important to detect cleanly all quarks
f
- f
From Joanne Hewitt
Look for deviation from straight line
SUSY and Extra Dimension Models can behave differently
Small uncertainties
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 GeV ILC (proposed initial energy).• All charginos and neutralinos should be seen at a 1 TeV 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
Measure Z΄ couplings given mass from LHC
Indirect sensitivity beyond LHC even at 500 GeV
Riemann
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 20th, 2004
Super conducting RF is accelerating technology choice (Global all aboard!)
TESLAThe Superconducting Electron-Positron
Linear Collider with an Integrated
X-Ray Laser Laboratory
Technical Design Report
DESY 2001 – 011 • ECFA 2001 -209
TESLA Report 2001 – 23 • TESLA-FEL 2001 - 05
March2 0 0 1
TESLAThe Superconducting Electron-Positron
Linear Collider with an Integrated
X-Ray Laser Laboratory
Technical Design Report
DESY 2001 – 011 • ECFA 2001 -209
TESLA Report 2001 – 23 • TESLA-FEL 2001 - 05
March2 0 0 1
TESLAThe Superconducting Electron-Positron
Linear Collider with an Integrated
X-Ray Laser Laboratory
Technical Design Report
DESY 2001 – 011 • ECFA 2001 -209
TESLA Report 2001 – 23 • TESLA-FEL 2001 - 05
March2 0 0 1
ILC Design Needed
Good Start
ICFA FALC
FALC Resource Board
ILCSC
GDEDirectorate
GDEExecutive Committee
GlobalR&D Program
RDR Design Matrix
GDER & D Board
GDEChange Control Board
GDEDesign Cost Board
GDE RDR / R&D Organization
GDE
Baseline Reference Design Report Jan July Dec 2006
Freeze ConfigurationOrganize for RDR
Bangalore
Review Design/Cost Methodology
Review InitialDesign / Cost Review Final
Design / CostRDR Document
Design and Costing PreliminaryRDR
Released
Frascati Vancouver Valencia
The ILC Baseline Machine
not to scale
~31 km
RTML ~1.6km
20mr
2mr BDS 5km
ML ~10km (G = 31.5MV/m)
x2e+ undulator @ 150 GeV (~1.2km)R = 955m
E = 5 GeV
Baseline Electron Source
Positron-style room-temperature
accelerating section
diagnostics section
standard ILC SCRF modules
sub-harmonic bunchers + solenoids
laser E=70-100 MeV
• 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 MeV and SRF linac to 5 GeV.
DC gun(s)
Baseline Positron Source
• Helical Undulator Based Positron Source with Keep Alive System– The undulator source will be placed at the 150 GeV point in
main electron linac. • This will allow constant charge operation across the foreseen centre-
of-mass energy operating range.
Primary e-
source
e-
DR
Target e- Dump
Photon Beam Dump
e+
DR
Auxiliary e- Source
Photon Collimators
Adiabatic Matching
Device
e+ pre-accelerator
~5GeV
150 GeV 100 GeV
HelicalUndulatorIn By-Pass
Line
PhotonTarget
250 GeV
Positron Linac
IP
Beam Delivery System
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 4th 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
Thales CPI Toshiba
Specification:
10MW MBK
1.5ms pulse
65% efficiency
ILC (XFEL @ DESY) has a very limited experience with these Klystrons. Production and operation of these Klystron are issues that needs to be addressed.
• Baseline (supported, at the moment, by GDE exec)– two BDSs, 20/2mrad, 2 detectors, 2 longitudinally separated IR
halls• Alternative 1
– two BDSs, 20/2mrad, 2 detectors in single IR hall @ Z=0• Alternative 2
– single IR/BDS, collider hall long enough for two push-pull detectors
Beam Delivery System (BDS)
Site power: 140 MW (500 GeV baseline)
Sub-Systems 43MW
Main Linacs 97MW
Cryogenics:
21MW
RF: 76MW
65%
78%
60%
Beam 22.6MW
Injectors
Damping rings
Auxiliaries
BDS
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
Qualifiedgradient
Operational gradient
Length* energy
MV/m MV/m Km GeV
initial TESLA 35 31.5 10.6 250
upgrade LL 40 36.0 +9.3 500
* assuming 75% fill factor
Total length of one 500 GeV linac 20km
3236
34
3535
Cavities for Module 6 @ DESY
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 S0, S1 and S2 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 (S0). 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 (S1).
– Build and test one or more ILC rf units at ILC beam parameters, high gradient, and full pulse rep rate (S2.1)
– To develop plans for an ILC Main Linac System Test consisting of several rf units (S2.2).
To achieve the goals, R&D plan will also strengthen the technical capabilities and infrastructure of collaborating institutions.
Global Plan Emerging
Back to Basics
Re-entrant
CornellKEK
Low Loss
Jlab
KEK
Tesla Shape
Need Multi-cells Next
New Shapes Breakthrough50 MV/m in Single Cells !
Lower Surface Magnetic Field & Lower Losses
Fabricated at Cornell
Higher Gradient in Single Cell: Eacc = 47 - 52 MV/m
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 using single cell cavities.
• It could eliminate the need to electro-polish
• Two 9-cell cavities are being fabricated.
Large Grain TESLA Cavity Shape SC, Chinese Nb
1.00E+09
1.00E+10
1.00E+11
0 5 10 15 20 25 30 35
Eacc [MV/m]
Q0
Test#1/2/3/4
Q - drop
Quench 29 MV/m
Quench @ 33.3 MV/m
Ningxia
Large Grain TESLA Cavity Shape SC, WC_Heraeus Nb
1.00E+09
1.00E+10
1.00E+11
0 5 10 15 20 25 30 35
Eacc [MV/m]
Q0
Test#2/4
Quench at 34.4 MV/m
HeraeusLarge Grain TESLA Cavity Shape SC#2, Ingot"D"
1.00E+09
1.00E+10
1.00E+11
0 5 10 15 20 25 30 35
Eacc [MV/m]
Q0
T=1.99K Series2
Test #1/2Test #1
Quench at 31.2 MV/m
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.
AES
ACCEL
60 Cavities (by FY07)
R&D Around the World
Three Regions-only look at DESY, KEK, US
Japan ATF/ATF2
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
The inter-cavity connection is done in class 10 cleanroom
The assembly of a string of 8 cavities into a string. Class 100 clean room
Facilities being setup at Fermilab as part of SMTF.
DESY String Assembly
INFN/DESY Co-Axial Tuner
Successfully operated with superstructures
Piezo-tuner integration still pending
Lorentz Force Detuning
Micro-phonics
The module assembly is well defined and about 10 modules have been made of several designs
ILC will need about 4000 modules.
DESY Module Assembly
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
• 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 ( IB1)• Single/large Crystal cavity development with TJNL
4 cavities received from ACCEL4 cavities on order at AES4 cavities expected from KEK
Bead pull RF Testing @ FNAL
Joint ANL/FNALBCP/EP Facility
ACCEL8_24may06
1.000E+09
1.000E+10
1.000E+11
0 5 10 15 20 25 30 35 40
Eacc (MV/M)
Q
Vertical Test of ACCEL Cavity
60 m BCP (nominal) + 50 m at ACCEL
Low Field: Q >5x1010, Eacc = 26 MV/m
Q
Eacc (Mv/m)
Fermilab ILC InfrastructureRF Measurement and Tuning
Cavity String Assembly Clean Room Class 10/100
Cryomodule Assembly @ MP9
ILCTA @ Fermilab
Fermilab Photo-injector
Eddy Current ScannerLLRF
Horizontal and Vertical Test Stands
Single Cavity Horizontal Test Stand
• Improved Design compared to DESY
• Bid Package is out
• Plan to install and commission at Meson in summer 06.
Multiple Cavities Vertical Test Stand
• Fermilab had designed VTS for DESY
• We are in process of designing a new VTS to be installed at IB1.
• It is expected to be operational in CY06.
Cryomodule Design & Fabrication• In FY05 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 FY08.
High Power testing of the cavities and the fabrication of 1st US cryomodule with new design 2008.
ILCTA @ Fermilab Phase 1: 1 RF Unit
1st RF Unit Integrated by US Laboratories and Universities
Photo-injectorPhase B
Diagnostics
40 MeV e- beam
Dump
SLAC
Fermilab
ILC LLRF, Control, Instrumentation, Feedback etc. ILC Institutions
Components provided by US and International Collaborators
Goal: Address S1 and S2 issues.
2nd RF Unit Produced and Integrated by ILC laboratories, Universities and Industries
HPR and Assembly
Alignment Cage
Jlab: Electro-polish Development for ILC
Jlab EP Cabinet
This facility has been commissioned.
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 GeV of linac• Reliably achieve > 35 MV/m and Q ~1x1010
Cryomodule design that can be mass produced• ~2000 required/500 GeV 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… 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 TeV 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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