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