Towards an International Linear Collider Barry Barish Caltech / GDE 25-July-07.

transcript

Towards an Towards an International Linear ColliderInternational Linear Collider

Barry BarishCaltech / GDE

25-July-07

25-July-07 Caltech DoE Review Global Design Effort 2

ILC -- Caltech

Exploring the Terascalethe 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

LHC: Low mass Higgs: H MH < 150 GeV/c2

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

ILC: Precision Higgs physics

Model-independent Studies

• mass

• absolute branching ratios

• total width

• spin

• top Yukawa coupling

• self coupling

Precision MeasurementsGarcia-Abia et al

The linear collider will measure the spin of any Higgs it can produce by measuring the energy dependence from threshold

Is it really the Higgs ?

Measure the quantum numbers. The Higgs must have spin zero !

Higgs Couplings at the ILC

Mass (GeV)

Higgs Coupling strength is proportional to Mass

e+e- : Studying the Higgsdetermine the underlying model

SM 2HDM/MSSM

Yamashita et al Zivkovic et al

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

main linacbunchcompressor

dampingring

source

pre-accelerator

collimation

final focus

extraction& dump

few GeV

few GeVfew GeV

250-500 GeV

Designing a Linear Collider

Superconducting RF Main Linac

The GDE Plan and Schedule

2005 2006 2007 2008 2009 2010

Global Design Effort Project

Baseline configuration

Reference Design

ILC R&D Program

Engineering Design

Expression of Interest to Host

International Mgmt

LHCPhysics

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

– 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

RDR ILC Schematic

RDR Design & “Value” Costs

SummaryRDR “Value” Costs

Total Value Cost (FY07)4.80 B ILC Units Shared

+1.82 B Units Site Specific

+14.1 K person-years

(“explicit” labor = 24.0 M person-hrs @ 1,700 hrs/yr)

1 ILC Unit = $ 1 (2007)

The reference design was “frozen” as of 1-Dec-06 for the purpose of producing the RDR, including costs.

It is important to recognize this is a snapshot and the design will continue to evolve, due to results of the R&D, accelerator studies and value engineering The value costs have already been reviewed twice

• 3 day “internal review” in Dec• ILCSC MAC review in Jan

Σ Value = 6.62 B ILC Units

Reference Design and Plan

Producing Cavities

Cavity Shape

Obtaining Gradientsingle cells

4th generation prototype ILC cryomodule

Cryomodules

TESLA cryomodule

The Main Linac

• Costs have been estimated regionally and can be compared. – Understanding differences require detail comparisons –

industrial experience, differences in design or technical specifications, labor rates, assumptions regarding

quantity discounts, etc.

– Three RF/cable penetrations every rf unit– Safety crossovers every 500 m– 34 kV power distribution

Main Linac Double Tunnel

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 total

Reference Design and Plan

Making Positrons

6km Damping Ring

10MW Klystrons

Beam Delivery and Interaction Point

Assessing the RDR

• Reviews (5 major international reviews + regional)– The Design: “The MAC applauds that considerable evolution

of the design was achieved … the performance driven baseline configuration was successfully converted into a cost conscious design.”

– The R&D Plan: “The committee endorses the approach of collecting R&D items as proposed by the collaborators, categorizing them, prioritizing them, and seeking contact with funding agencies to provide guidelines for funding.

– International Cost Review (Orsay): Supported the costing methodology; considered the costing conservative in that they identify opportunities for cost savings; etc.

• Final Steps– The final versions of Executive Summary, Reference Design

Report and Companion Document were submitted to FALC (July), and finally will be given to ILCSC and ICFA (August).

Schedule for the ILC?

• Our technically driven timeline is – Construction proposal in 2010 – Construction start in 2012– Construction complete in 2019

“Completing the R&D and engineering design, negotiating an internationalstructure, selecting a site, obtainingfirm financial commitments, and building a machine could take us well into the mid-2020s, if not later,”

Technically Driven Timeline

August

BCD Construction Startup

2006 2010 2014 2018

RDR EDRBeginConst

EndConst

EngineerDesign

Civil Construction Timeline

CMS assembly approach:• Assembled on the surface in parallel with underground work• Allows pre-commissioning before lowering• Lowering using dedicated heavy lifting equipment• Potential for big time saving• Reduces size of required underground hall

On-surface Detector Assembly CMS approach

August

All regions require ~ 5 yrs

Construction Startup

Siting Plan being Developed

2006 2010 2014 2018

RDR EDRBeginConst

EndConst

EngineerDesign

Site Prep

Site Select

Situation : in solid rock, close to existing institute, close to the city

of Chicago and international airport, close to railway and

highway networks.

Geology : Glacially derived deposits overlaying Bedrock. The

concerned rock layers are from top to bottom the Silurian

dolomite, Maquoketa dolomitic shale, and the Galena-

Platteville dolomites.

Depth of main tunnels : Average ~ 135 m

Americas Fermilab Sample Site

~ 5.5 km

Central Area fits inside the Fermilab boundary

Site Characterization of the Central Area can be done

~ Boundary of Fermilab

Preconstruction Plan: Fermilab

August

All regions ~ 5 yrs

2006 2010 2014 2018

RDR EDRBeginConst

EndConst

EngineerDesign

Site Prep

Site Select

R & D -- Industrialization

The Task Forces

• The Task Forces were put together successively over a period of five months:

S0/S1-Cavities, Cryomodule

S2 -Cryomodule String Tests S3 -Damping Rings S4 -Beam Delivery System S5-Positron Source

S6-Controls, not yet activeS7-RF

• Working in close collaboration with the Engineering and Risk Assessment team.

Module Test – Results

E Cloud – Results

Schedule in Graphical Form2009 2012 2015 2018

ConstructionSchedule

CryomoduleProduction

RF System Tests

August

All regions ~ 5 yrs

2006 2010 2014 2018

RDR EDRBeginConst

EndConst

EngineerDesign

Site Prep

Site Select

Gradient

e-CloudCryomoduleFull Production

System Tests

& XFEL

Detector Install

Detector Construct

Detector Concepts

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]

detectorB

may be accessible during run

accessible during run Platform for electronic and

services (~10*8*8m). Shielded (~0.5m of concrete) from five sides. Moves with detector. Also provide vibration isolation.

Concept of IR hall with two detectors

The concept is evolving and details being worked out

detectorA

August

All regions ~ 5 yrs

2006 2010 2014 2018

RDR EDRBeginConst

EndConst

EngineerDesign

Site Prep

Site Select

Gradient

e-CloudCryomoduleFull Production

System Tests

& XFEL

Detector Install

Detector Construct

Pre-Operations

Conclusions

• The ILC design is proceeding toward an engineering design by 2010. (Goal: Ready to propose construction when LHC results justify).

• R&D program is being globally coordinated to determine gradient, electron cloud, industrialization, mass production. (Resources are regional, by country and laboratory).

• Detector R&D also very important to be able to fully exploit the ILC (e.g. spatial & energy resolution) (Needs improved coordination, better regional balance).

• Caltech effort is myself + some student projects. But, we are in excellent position to ramp up as desired and the when time is right.

Towards an International Linear Collider Barry Barish Caltech / GDE 25-July-07.

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