the ilc global design effortbcbact/talks05/japan... · 2005-07-24 · 28-june-05 ilc industrial...

The ILC Global Design Effort

Barry Barish

ILC Industrial ForumJapan

28-June-05

28-June-05 ILC industrial Forum (Japan) - Barish 2

Why e+e- Collisions?

• elementary particles• well-defined

– energy,– angular momentum

• uses full COM energy• produces particles

democratically• can mostly fully

reconstruct events


A Rich History as a Powerful Probe


The Energy Frontier


Why a TeV Scale e+e- Accelerator?

• Two parallel developments over the past few years (the technology)

– Designs and technology demonstrations have matured on two technical approaches for an e+e-

collider that are well matched to our present understanding of the physics.


GLC GLC/NLC Concept

• The main linacs operate at an unloaded gradient of 65 MV/m, beam-loaded to 50 MV/m.

• The rf systems for 500 GeV c.m. consist of 4064 75 MW Periodic Permanent Magnet (PPM) klystrons arranged in groups of 8, followed by 2032 SLED-II rf pulse compression systems


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.


Which Technology to Chose?

– 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 required uniting behind one technology, and then working toward a unified global design based on the recommended technology.


International Technology Review Panel


Evaluate a Criteria Matrix

• The panel analyzed the technology choice through studying a matrix having six general categories with specific items under each:– the scope and parameters specified by the ILCSC; – technical issues; – cost issues; – schedule issues; – physics operation issues; – and more general considerations that reflect the

impact of the LC on science, technology and society


The 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).


The Technology Recommendation

• The recommendation was presented to ILCSC & ICFA on August 19 in a joint meeting in Beijing.

• ICFA unanimously endorsed the ITRP’srecommendation on August 20


The Community then Self-Organized

Nov 13-15, 2004

The Global Design Effort

Formal organization begun at LCWS 05 at Stanfordin March 2005 when I became director of the GDE

Technically Driven Schedule


GDE – Near Term Plan

• Schedule• Begin to define Configuration (Aug 05) • Baseline Configuration Document by end of 2005-----------------------------------------------------------------------• Put Baseline under Configuration Control (Jan

06) • Develop Reference Design Report by end of 2006

• Three volumes -- 1) Reference Design Report; 2) Shorter glossy version for non-experts and policy makers ; 3) Detector Concept Report


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


Experimental Test Facility - KEK• Prototype Damping Ring for X-band Linear Collider

• Development of Beam Instrumentation and Control


Towards the ILC Baseline Design


Cost Breakdown by Subsystem

cf31%

structures18%rf

12%

systems_eng8%

installation&test7%

magnets6%

vacuum4%

controls4%

cryo4%

operations4%

instrumentation2%

Civil

SCRF Linac


TESLA Cavity

9-cell 1.3GHz Niobium Cavity

Reference design: has not been modified in 10 years

~1m


What Gradient to Choose?


Gradient

Results from KEK-DESY collaboration

must reduce spread (need more statistics)

single

-cel

l m

easu

rem

ents

(in

nin

e-ce

ll ca

vities

)


(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


How Costs Scale with Gradient?

Relative C

ost

Gradient MV/m

2

0

$ l inc ryo

a GbG 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)


Evolve the CavitiesMinor Enhancement

Low Loss Design

Modification to cavity shape reduces peak B field. (Asmall Hp/Eacc ratio around 35Oe/(MV/m) must be designed).

This generally means a smaller bore radius

Trade-offs (Electropolishing, weak cell-to-cell coupling, etc) KEK currently producing prototypes


New Cavity Design

More radical concepts potentially offer greater benefits.

But require time and major new infrastructure to develop.

2×8 cell Super-structure

Re-entrant

single-cell achieved45.7 MV/m Q0 ~1010

(Cornell)


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


ILC Civil Program

U.S., Japanese and European engineers are developing 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


Parameters of Positron Sources

rep rate # of bunches per pulse

# of positrons per bunch

# of positrons per pulse

TESLA TDR 5 Hz 2820 2 · 1010 5.6 · 1013

NLC 120 Hz 192 0.75 · 1010 1.4 · 1012

SLC 120 Hz 1 5 · 1010 5 · 1010

DESY positron source 50 Hz 1 1.5 · 109 1.5 · 109


Positron Source

• Large amount of charge to produce

• Three concepts:– undulator-based (TESLA TDR baseline)

– ‘conventional’– laser Compton based


Strawman Final Focus


Technologies for the ILC

• Large Scale Project Characterization– Large Project Management– Precision Engineering– International Coordination

• Industrialization– Civil Construction & Infrastructure– Cryogenics– Superconducting RF structures, couplers, etc– Electronics and Control Systems– Large Scale Computing

the ilc global design effortbcbact/talks05/japan... · 2005-07-24 · 28-june-05 ilc industrial...

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