the ilc global design effort

The ILC Global Design Effort

Barry BarishSPC Meeting

CERN 13-Aug-05

13-Sept-05 Scientific Policy Committee - CERN 2

Why a TeV 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 TeV LC and the LHC science.


Electroweak Precision Measurements

LEP results strongly point to a low mass Higgs and an energy scale for new physics < 1TeV

0

2

4

6

10020 400

mH GeV

Excluded Preliminary

had =(5)

0.027610.00036

0.027470.00012

Without NuTeV

theory uncertainty

Winter 2003




– 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 TeV LC and the LHC science.


The 500 GeV Linear Collider Spin Measurement

LHC should discover the Higgs

The linear collider will measure the spin of any Higgs it can produce.

The process e+e– HZ can be used to measure the spin of a 120 GeV Higgs particle. The error bars are based on 20 fb–1 of luminosity at each point.

LHC/ILC Complementarity

The Higgs must have spin zero


Extra Dimensions

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.

Linear collider

LHC/ILC Complementarity




– 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.


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.


• The JLC-X and NLC are essentially a unified single design with common parameters

• The main linacs are based on 11.4 GHz, room temperature copper technology.

GLCGLC/NLC Concept


Which Technology to Choose?

– 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.


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).


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


The Community Self-Organized

Nov 13-15, 2004


KEK Workshop Organization

• WG1 Parms & layout• WG2 Linac• WG3 Injectors• WG4 Beam Delivery• WG5 High Grad. SCRF• WG6 Communications

• WG1 LET beam dynamics• WG2 Main Linac• WG3a Sources• WG3b Damping Rings• WG4 Beam Delivery• WG5 SCRF Cavity Package• WG6 Communications

Birth of the GDEand Preparation for Snowmass


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.)


GDE MembersChris Adolphsen, SLACJean-Luc Baldy, CERNPhilip Bambade, LAL, OrsayBarry Barish, CaltechWilhelm Bialowons, DESYGrahame Blair, Royal HollowayJim Brau, University of OregonKarsten Buesser, DESYElizabeth Clements, FermilabMichael Danilov, ITEPJean-Pierre Delahaye, CERN, Gerald Dugan, Cornell UniversityAtsushi Enomoto, KEKBrian Foster, Oxford UniversityWarren Funk, JLABJie Gao, IHEPTerry Garvey, LAL-IN2P3Hitoshi Hayano, KEKTom Himel, SLACBob Kephart, FermilabEun San Kim, Pohang Acc LabHyoung Suk Kim, Kyungpook Nat’l UnivShane Koscielniak, TRIUMFVic Kuchler, FermilabLutz Lilje, DESY

Tom Markiewicz, SLACDavid Miller, Univ College of LondonShekhar Mishra, FermilabYouhei Morita, KEKOlivier Napoly, CEA-SaclayHasan Padamsee, Cornell UniversityCarlo Pagani, DESYNan Phinney, SLACDieter Proch, DESYPantaleo Raimondi, INFNTor Raubenheimer, SLACFrancois Richard, LAL-IN2P3Perrine Royole-Degieux, GDE/LALKenji Saito, KEKDaniel Schulte, CERNTetsuo Shidara, KEKSasha Skrinsky, Budker InstituteFumihiko Takasaki, KEKLaurent Jean Tavian, CERNNobu Toge, KEKNick Walker, DESYAndy Wolski, LBLHitoshi Yamamoto, Tohoku UnivKaoru Yokoya, KEK

49 members

Americas 16 Europe 21 Asia 12


Participation in Snowmass

670 Scientists attended two week

workshopat

Snowmass


GDE Organization for Snowmass)

•W

G1

LE

T b

dy

n.

•W

G2

Ma

in L

ina

c

•W

G3

a S

ou

rces

•W

G3

b D

R

•W

G4

BD

S

•W

G5

Ca

vity• GG1 Parameters• GG2 Instrumentation• GG3 Operations & Reliability• GG4 Cost & Engineering• GG5 Conventional Facilities• GG6 Physics Options

Technical sub-systemWorking Groups

Global Group

Provide input

The GDE Plan and Schedule 2005 2006 2007 2008 2009 2010

Global Design Effort Project

Baseline configuration

Reference Design

ILC R&D Program

Technical Design

Expression of Interest to Host

International Mgmt

LHCPhysics

CLIC


main linacbunchcompressor

dampingring

source

pre-accelerator

collimation

final focus

IP

extraction& dump

KeV

few GeV

few GeVfew GeV

250-500 GeV

Starting Point for the GDE

Superconducting RF Main Linac


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


Higgs Coupling and Extra Dimensions• ILC precisely measures Higgs interaction strength with standard model particles.

• 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 models predict that the effect on each particle would be exactly the same size.

• The red error bars indicate the level of precision attainable at the ILC for each particle

• Sufficient to discover extra dimensional physics.


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


Parametric Approach

• Parametric approach to design– machine parameters : a space to optimize the machine

– Trial parameter space, being evaluated by subsystems

– machine design : incorporate change without redesign; incorporates value engineering, trade studies at each step to minimize costs


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


The Key Decisions

Critical choices: luminosity parameters & gradient


Cost Drivers

cf31%

structures18%rf

12%

systems_eng8%

installation&test7%

magnets6%

vacuum4%

controls4%

cryo4%

operations4%

instrumentation2%

Civil

SCRF Linac


What Gradient to Choose?


How Costs Scale with Gradient?

Relative

Co

st

Gradient MV/m

2

0

$ lincryo

a Gb

G Q

35MV/m is close to optimum

Japanese are still pushing for 40-45MV/m

30 MV/m would give safety margin

C. Adolphsen (SLAC)


Cavity Fabrication


Gradient

Results from KEK-DESY collaboration

must reduce spread (need more statistics)

single

-cell

measu

rem

ents

(in

nin

e-c

ell

cavit

ies)


Improved Fabrication


Improved ProcessingElectropolishing


(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

Electro-polishing


Baseline Gradient


Improved Cavity Shapes


Large Grain Single Crystal Nb Material


ILC Siting and Civil Construction

• 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 choosing between three final sites– Europe sample sites --- CERN and DESY


1 vs 2 Tunnels

• Tunnel must contain– Linac Cryomodule– RF system– Damping Ring Lines

• Save maybe $0.5B

• Issues– Maintenance– Safety– Duty Cycle


Possible Tunnel Configurations

• One tunnel of two, with variants ??


ILC Civil Program

Civil engineers from all three regions working to develop methods of analyzing the siting issues and comparing sites.

The current effort is not intended to select a potential site, but rather to understand from the beginning how the features of sites will effect the design, performance and cost


Baseline Klystrons

ThalesCPI

Toshiba

Available today: 10 MW Multi-Beam Klystrons (MBKs) that operate at up to 10 Hz


Improved Klystron ?

10 MW Sheet BeamKlystron (SBK)Parameters similar to

10 MW MBK

Low Voltage10 MW MBK

Voltage e.g. 65 kVCurrent 238AMore beams

Perhaps use a Direct Switch Modulator

5 MW Inductive Output Tube (IOT)

Drive

Out

put

IOT

Klystron

SLAC CPI

KEK


With two-level power division and proper phase lengths, expensive circulators can be eliminated. Reflections from pairs of cavities are directed to loads. Also, fewer types of hybrid couplers are needed in this scheme. There is a small increased risk to klystrons. (Total reflection from a pair of cavities sends < 0.7% of klystron power back to the klystron.)

Similar to TDR and XFEL scheme.

BASELINE DESIGN

POSSIBLE IMPROVEMENT?

RF Distribution


Beamsize Growth Study (cumulative after feedback)

30 min ground.

+ Undulator

+ Component

jitter

+ 5 Hz

ground.

+ Kicker, current,

energy jitter, BPM resol.


Availability Studies1 vs 2 tunnels


Improving Mean Time Between Failures


Damping Rings: Three variants

3km

6km

17 km ‘dogbone’


Beam Delivery, MDI

Strawman solution (BCD recommendation)

Appears to work for nearly all suggested parameter sets:Exceptions:• 1 TeV high-luminosity (new parameter set suggested for 20mrad)• 2 mrad extraction has problems with high disruption sets


Industrial Studies

• Industrial studies in three regions are essential.

– Important to understand industrial costs– Important to examine potential cost reductions– Need to think about what studies are needed and when– Focus on the cost drivers for ILC, important for cost estimate – Focus on places where there is technical risk to the project goals– ILC need a point-of-contact and a plan for industrial studies

2nd ILC Industrial Forum Meeting is scheduled to be held atFermilab Sept. 21st and 22nd, 2005.


• Three concepts under study

• Typically requires factors of two or so improvements in granularity, resolution, etc. from present generation detectors

• Focused R&D program required to develop the detectors -- end of 2005

• Detector Concepts will be used to simulate performance of reference design vs physics goals next year.

Detector Concepts and Challenges


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.


Creating an International Project

• Several Studies and Plans for ILC – OECD (Organization for Economic Cooperation and

Development)• “A template for Establishing, Funding and Managing an

International Scientific Research Project Based on an Agreement Between Governments and Institutions”

– Features a template that covers all aspects of creating agreements for an international collaboration, in particular formal agreements, funding arrangements, central structure and using existing institutions


OECD International Project Template

Memorandum of Understanding

Participants Participants Participants Host Country

Secretariat Host

Host Agreement

The Collaboration

Governing Board

Scientific and Technical Advisory Bodies (optional)

Secretariat

Director

Staff

Country Agreement



• Several Studies and Plans for ILC – TESLA proposed plan for Project Organization

• “Organization and Management of an International Collaboration on the TESLA Linear Collider”

– Features a “Global Accelerator Network”, which is basically a collaboration between institutions where as much as possible the participation is treated as an extension of the laboratory programs and even the accelerator is to be run locally from the collaborating laboratories.


TESLA Proposed Project Organization



• Several Studies and Plans for ILC – ECFA EUROPEAN COMMITTEE FOR FUTURE

ACCELERATORS subcomittee EUROPEAN LINEAR COLLIDER STEERING GROUP

• “Report of the Sub-group on Organizational Matters”

– Features a detailed breakdown of top level governance and project management, how they relate to each other. It is based on regional organizations; mostly in-kind contributions; shared central management, oversight, responsibility. It is concerned with Europe and how to do it within European Labs (CERN) and structures


ECFA ILC Governance and Management


Remarkable progress in the past two years toward realizing an international linear collider:

important R&D on accelerator systems

definition of parameters for physics

choice of technology

start the global design effort

funding agencies are engaged

Many major hurdles remain before the ILC becomes a reality (funding, site, international organization, and most importantly, a technical design and construction plan)

The time scale for ILC project readiness is consistent with early results from LHC and CLIC feasability studies.

Conclusions

the ilc global design effort

Documents

tev scale e e accelerator

superconducting technology

recommended technology

lhc science

process e e hz

low mass higgs

superconducting rf technology

tev lc