International Linear Colllider

Global Design Effort

Barry BarishSLAC ILC Group

5-May-05

5-May-05 SLAC 2

main linacbunchcompressor

dampingring

source

pre-accelerator

collimation

final focus

IP

extraction& dump

KeV

few GeV

few GeVfew GeV

250-500 GeV

Starting Point

Superconducting RF Main Linac

5-May-05 SLAC 3

“Target” 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

5-May-05 SLAC 4

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.

5-May-05 SLAC 5

TESLA Cavity

• RF accelerator structures consist of close to 21,000 9-cell niobium cavities operating at gradients of 23.8 MV/m (unloaded as well as beam loaded) for 500 GeV c.m. operation.

• The rf pulse length is 1370 µs and the repetition rate is 5 Hz. At a later stage, the machine energy may be upgraded to 800 GeV c.m. by raising the gradient to 35 MV/m.

5-May-05 SLAC 6

TESLA Single Tunnel Layout

• The TESLA cavities are supplied with rf power in groups of 36 by 572 10 MW klystrons and modulators.

5-May-05 SLAC 7

Reference Points for the ILC Design

33km47 km

TESLA TDR500 GeV (800 GeV)

US Options Study500 GeV (1 TeV)

5-May-05 SLAC 8

Experimental Test Facility - KEK

• Prototype Damping Ring for X-band Linear Collider

• Development of Beam Instrumentation and Control

5-May-05 SLAC 9

Evaluation: Technical Issues

5-May-05 SLAC 10

TESLA Test Facility Linac

laser driven electron gun

photon beam diagnostics

undulatorbunch

compressor

superconducting accelerator modules

pre-accelerator

e- beam diagnostics

e- beam diagnostics

240 MeV 120 MeV 16 MeV 4 MeV

5-May-05 SLAC 11

ILC Design Issues

First Consideration : Physics Reach

ILC Parameters

Energy Reach

2cm fill linac RFE b L G

Luminosity RF AC BS

cm y

PL

E

5-May-05 SLAC 12

Working Parameter Set“Point Design”

Center of Mass Energy 500 1000 GeV

Design Luminosity 2 3 1034cm-2sec-1

Linac rf frequency GHzAccelerating gradient MV/mPulse repetition rate HzBunches/pulseBunch separation nsec

Particles/bunch x1010

Bunch train length msecBeam power 11 23 MW/beam

sx/sy at IP 655/7 554/4 nm

Site AC power 180 356 MW

5

1.3

2866

2820307

30

5-May-05 SLAC 13

GDE will do a “Parametric” Design

nom low N lrg Y low P

N 1010 2 1 2 2

nb2820 5640 2820 1330

ex,ymm, nm 9.6, 40 10,30 12,80 10,35

bx,ycm, mm 2, 0.4 1.2, 0.2 1, 0.4 1, 0.2

sx,ynm 543, 5.7 495, 3.5 495, 8 452, 3.8

Dy18.5 10 28.6 27

dBS% 2.2 1.8 2.4 5.7

szmm 300 150 500 200

PbeamMW 11 11 11 5.3

L 1034 2 2 2 2

Range of parametersdesign to achieve 21034

5-May-05 SLAC 14

Maximum Luminosity

nom low N lrg Y low P High L

N 1010 2 1 2 2 2

nb 2820 5640 2820 1330 2820

x,y mm, nm 9.6, 40 10,30 12,80 10,35 10,30

x,y cm, mm 2, 0.4 1.2, 0.2 1, 0.4 1, 0.2 1, 0.2

sx,y nm 543, 5.7 495, 3.5 495, 8 452, 3.8 452, 3.5

Dy 18.5 10 28.6 27 22

BS % 2.2 1.8 2.4 5.7 7

sz mm 300 150 500 200 150

Pbeam MW 11 11 11 5.3 11

L 1034 2 2 2 2 4.9!

5-May-05 SLAC 15

Towards the ILC Baseline Design

5-May-05 SLAC 16

e- Beam Transport XFEL

e- Damping Ring

HEP & XFEL Experiments

e- Main LINAC e+ Beam delivery e+ Main LINAC

e+ Damping Ringe- Sources e+ Beam Transport

e- Beam delivery

e+ Source

e- Switchyard XFEL

PreLinac

PreLinac

Beam DumpsDESY site Westerhorn

TESLA machine schematic view

Power Water & Cryogenic Plants

Machine cost distribution

Main LINAC Modules

Main LINAC RF System

Civil Engineering

MachineInfrastructure

X FELIncrementals

Damping Rings

HEP Beam Delivery

AuxiliarySystems

Injection System

1131

~ 33 km

587 546

336241 215

124 101 97

Million Euro

TESLA Cost Estimate3,136 M€ (no contingency, year 2000) + ~7000 person years

5-May-05 SLAC 17

RF SC Linac ChallengesEnergy: 500 GeV, upgradeable to 1000 GeV

• RF Accelerating Structures– Accelerating structures must support the desired gradient in an

operational setting and there must be a cost effective means of fabrication.

– ~17,000 accelerating cavities/500 GeV

– Current performance goal is 35 MV/m, (operating at 30 MV/m)

• Trade-off cost and technical risk.

1 mRisk

Cos

t

~T

heor

etic

al M

ax

5-May-05 SLAC 18

(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

5-May-05 SLAC 19

Gradient

Results from KEK-DESY collaboration

must reduce spread (need more statistics)

single

-cell

measu

rem

ents

(in

nin

e-c

ell

cavit

ies)

5-May-05 SLAC 20

New Cavity Shape for Higher Gradient?

TESLA Cavity

• A new cavity shape with a small Hp/Eacc ratio around35Oe/(MV/m) must be designed. - Hp is a surface peak magnetic field and Eacc is the electric field gradient on the beam axis.

- For such a low field ratio, the volume occupied by magnetic field in the cell must be increased and the magnetic density must be reduced.

- This generally means a smaller bore radius. - There are trade-offs (eg. Electropolishing, weak cell-to-cell

coupling, etc)

Alternate Shapes

5-May-05 SLAC 21

Gradient vs Length

• Higher gradient gives shorter linac – cheaper tunnel / civil engineering– less cavities – (but still need same # klystrons)

• Higher gradient needs more refrigeration– ‘cryo-power’ per unit length scales as G2/Q0

– cost of cryoplants goes up!

5-May-05 SLAC 22

Klystron Development

THALUS

CPITOSHIBA

10MW 1.4ms Multibeam Klystrons~650 for 500 GeV+650 for 1 TeV upgrade

5-May-05 SLAC 23

Towards the ILC Baseline Design

Not cost drivers

But can be L performancebottlenecks

Many challenges!

5-May-05 SLAC 24

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

5-May-05 SLAC 25

Positron Source

• Large amount of charge to produce

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

– ‘conventional’ – laser Compton based

5-May-05 SLAC 26

5-May-05 SLAC 27

5-May-05 SLAC 28

5-May-05 SLAC 29

Strawman Final Focus

5-May-05 SLAC 30

International/Regional Organization

ILC-Americas Regional Team Regional Director and Deputy Institutional ILC Managers for major instiutional members

CornellILC-NSF PI

TRIUMFILC-CanadaManager

NSF-funded Institutions

Canadian Institutions

Lead Labs

Work Package

Oversight ILCSC

GDE - Director

RegionalUSLCSG

FundingAgencies

FNALILC-FNALManager

WP 1.FNAL

WP 1.ANL

WP 3.FNAL

SLACILC-SLACManager

WP 2.SLAC

WP 2.BNL

WP 3.SLAC

communications

ILC-Asia ILC-Europe

International

Regional

5-May-05 SLAC 31

Fall 2002: ICFA created the International Linear Collider Steering Committee (ILCSC) to guide the process for building a Linear Collider. Asia, Europe and North America each formed their own regional Steering Groups (Jonathan Dorfan chairs the North America steering group).

Physics and Detectors Subcommittee (AKA WWS) Jim Brau, David Miller, Hitoshi Yamamoto, co-chairs (est. 1998 by ICFA as free standing group)

International Linear Collider Steering CommitteeMaury Tigner, chair

ParametersSubcommitteeRolf Heuer, chair

(finished)

Accelerator SubcommitteeGreg Loew, chair

Comunicationsand OutreachNeil Calder et al

Technology Recommendation Panel

Barry Barish, chair (finished)

Global Design Initiative

organization Satoshi Ozaki, chair (finished)

GDI central team site

evaluation Ralph Eichler,

chair

GDI central team director

search committee Paul Grannis,

chair

5-May-05 SLAC 32

Attendees: Son (Korea); Yamauchi (Japan); Koepke (Germany); Aymar (CERN); Iarocci (CERN Council); Ogawa (Japan); Kim (Korea); Turner (NSF - US); Trischuk (Canada); Halliday (PPARC); Staffin (DoE – US); Gurtu (India)

Guests: Barish (ITRP); Witherell (Fermilab Director,)

“The Funding Agencies praise the clear choice by ICFA. This recommendation will lead to focusing of the global R&D effort for the linear collider and the Funding Agencies look forward to assisting in this process.

The Funding Agencies see this recommendation to use superconducting rf technology as a critical step in moving forward to the design of a linear collider.”

FALC is setting up a working group to keep a close liaison with the Global Design Initiative with regard to funding resources.

The cooperative engagement of the Funding Agencies on organization, technology choice, timetable is a very strong signal and encouragement.

Working with Funding Agency (FALC)

5-May-05 SLAC 33

GDE – Near Term Plan

• Organize the ILC effort globally– Undertake making a “global design” over the next few years

for a machine that can be jointly implemented internationally. • Snowmass Aug 05 --- Begin to define Configuration (1st Step)

• GDE Dec 05 --- Baseline Configuration document by end of 2005

• Put Baseline under Configuration Control

• Conceptual Design of Baseline by end of 2006– Include site dependence – 3 or more sample sites– Detector Design Concept / Scope (1 vs 2, options, etc)– Reliable Costs -- emphasis during design on cost consciousness ---

value Engineering, trade studies, industrialization, etc

– Coordinate worldwide R & D efforts, in order to demonstrate and improve the performance, reduce the costs, attain the required reliability, etc. (Proposal Driven to GDE)