Transcript
Page 1: Linear Collider – Next Steps in R&D

Linear Collider – Next Steps in R&D

Nan PhinneySLAC

many slides courtesy of G. Geshonke EPS 2009

C. Adolphsen, F. Zimmermann and others

Page 2: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 2

Linear Collider Luminosity

nb : bunches / train

N: Particles / bunchA: beam cross section at IPHD: beam-beam enhancement factor

BUT Pbeam = Pwall plug * ηconversion efficiency

two-linac length 2L ~ ECM/(Ffilling factor x Ggradient)

This points to the critical issues in optimizing the cost of the collider→ Efficiency sets the electrical power required for a given beam power → Accelerating gradient sets the length required for a given energy

ILC & CLIC take different routes to high efficiency and high gradient

where

Page 3: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 3

The ILC Reference Design

200-500 GeV centre-of-massLuminosity: 2×1034 cm-2s-1

Based on accelerating gradient of 31.5 MV/m(1.3GHz SCRF)

~31 km

N.Walker

Page 4: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 4

SCRF Technology Required

Parameter Value

C.M. Energy 500 GeV

Peak luminosity 2x1034 cm-2s-1

Beam Rep. rate 5 Hz

Pulse time duration 1 ms

Average beam current 9 mA (in pulse)

Av. field gradient 31.5 MV/m# 9-cell cavity 14,560# cryomodule 1,680# RF units 560

A. Yamamoto

Page 5: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 5

R. Geng, JLab

BREAKING NEWS !!!!

JLAB press release today announced the first US built cavity to reach ILC specs

Page 6: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 6

SRF Test Facilities

KEK, JapanDESYFNAL

TTF/FLASH~1 GeVILC-like beamILC RF unit(* lower gradient)

NML facilityUnder constructionfirst beam 2010ILC RF unit test

STF (phase I & II)Under constructionfirst beam 2011ILC RF unit test

A. Yamamoto

Page 7: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 7

New L-Band Station at ESB: Marx Modulator and 10 MW Toshiba Multi-Beam Klystron

C. Adolphsen

Page 8: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 8

Sheet Beam Klystron Development

An elliptical beam is focused in a periodic permanent magnet stack that is interspersed with rf cavities

ElectronBeam

PermanentMagnet Cell

RF cavity

Magnetic Shielding

Lead Shielding

Gun in assembly

Page 9: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 9

Coupler Assembly and Processing

Class 10 Cleanroom @SLAC

Processed in pairs – shipped

to FNAL

Page 10: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 10

RF Distribution Modules with variable tap off

Variable tap off allows power adjustment to each cavity

4 2-cavity modules sent to FNAL

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2009 SLUO Meeting Sept 17, 2009 Page 11

Two 4.5 to 5.5 m diameter tunnels spaced by ~7 m.

RDR Baseline Tunnel Layout

Accelerator Tunnel Service TunnelPenetrations(every ~12 m)

one klystron feeding 26 cavities

C. Adolphsen

Page 12: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 12

Klystron Cluster Concept

RF power “piped” into accelerator tunnel every 2.5 km

Service tunnel eliminated

Electrical and cooling systems simplified

Concerns: power handling, LLRF control coarseness

Same as baseline

C. Adolphsen

Page 13: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 14 14

ILC R&D plan

Page 14: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 15

The CLIC Two Beam Scheme

Two Beam Scheme:Drive Beam supplies RF power

• 12 GHz bunch structure• low energy (2.4 GeV - 240 MeV)• high current (100A)

CLIC parameters:

Accelerating gradient: 100 MV/m RF frequency: 12 GHzPulse length 240 ns, 50 Hz

active length for 1.5 TeV: 15 km

G. Geshonke

Page 15: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 16

CLIC Drive Beam generation

EPS 2009 G.Geschonke, CERN

Accelerate long bunch train with low bunch rep rate (500 MHz) with low frequency RF (1 GHz) (klystrons)

interleave bunches between each otherto generate short (280 ns) trains with high bunch rep rate (12 GHz)

G. Geshonke

Page 16: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 17

The full CLIC scheme

e+ injector, 2.4 GeV

e- injector2.4 GeV

CLIC 3 TeV

e+ main linace- main linac , 12 GHz, 100 MV/m, 21.02 km

BC2BC2

BC1

e+

DR365m

e-

DR365m

booster linac, 9 GeV

decelerator, 24 sectors of 876 m

IP

BDS2.75 km

BDS2.75 km

48.3 km

drive beam accelerator2.38 GeV, 1.0 GHz

combiner rings Circumferences delay loop 72.4 m

CR1 144.8 mCR2 434.3 m

CR1CR2

delayloop

326 klystrons33 MW, 139 s

1 km

CR2delayloop

drive beam accelerator2.38 GeV, 1.0 GHz

326 klystrons33 MW, 139 s

1 km

CR1

TAR=120m

TAR=120m

245m 245m

e+

PDR365m

e-

PDR365m

e+ injector, 2.4 GeV

e- injector2.4 GeV

CLIC 3 TeV

e+ main linace- main linac , 12 GHz, 100 MV/m, 21.02 km

BC2BC2

BC1

e+

DR365m

e-

DR365m

booster linac, 9 GeV

decelerator, 24 sectors of 876 m

IP

BDS2.75 km

BDS2.75 km

48.3 km

drive beam accelerator2.38 GeV, 1.0 GHz

combiner rings Circumferences delay loop 72.4 m

CR1 144.8 mCR2 434.3 m

CR1CR2

delayloop

326 klystrons33 MW, 139 s

1 km

drive beam accelerator2.38 GeV, 1.0 GHz

combiner rings Circumferences delay loop 72.4 m

CR1 144.8 mCR2 434.3 m

CR1CR1CR2

delayloop

326 klystrons33 MW, 139 s

1 km

CR2delayloop

drive beam accelerator2.38 GeV, 1.0 GHz

326 klystrons33 MW, 139 s

1 km

CR1CR1CR1

TAR=120m

TAR=120m

245m 245m

e+

PDR365m

e-

PDR365m

Not to scale! G. Geshonke

Page 17: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 18

optimum CLIC: 100 MV/m at 12 GHz

Structure limits: • RF breakdown – scaling• RF pulse heating

Optimisation:

Beam dynamics:• emittance preservation – wake fields• Luminosity, bunch population, bunch spacing• efficiency – total powerFigure of merit:• Luminosity per linac input powertake into account cost model

100 MV/m 12 GHz chosen,previously 150 MV/m, 30 GHz

A. Grudiev

Page 18: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 19

CLIC Accelerating Module

19

Drive Beam

Main Beam

Transfer lines

Main Beam

Drive Beam

G. Riddone

Page 19: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 20

CLIC Accelerating structures

Technologies:Brazed disks - milled quadrants

Objective:• Withstand 100 MV/m without damage• breakdown rate < 10-7

• Strong damping of HOMs

Collaboration: CERN, KEK, SLACW. Wunsch

Page 20: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 21

Nominal performance of Accelerating StructuresDesign@CERN, Built/Tested @KEK, SLAC

95 100 105 110 11510

-7

10-6

10-5

10-4

Unloaded Gradient: MV/m

BK

D R

ate:

1/p

ulse

/m

BKD Rate for 230ns

250hrs

500hrs

1200hrs

900hrs

CLIC target

KEK

SLAC

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2009 SLUO Meeting Sept 17, 2009 Page 22

Power Extraction : PETS

8 Sectorsdampedon-off possibility

Status:CTF3: up to 45 MW peak (3 A beam,recirculation)SLAC: 125 MW @ 266 ns

Special development for CLIC

Travelling wave structures Small R/Q : 2.2 kW/m (accelerating structure: 15-18 kW/m) 100 A beam current

136 MW RF @ 240 ns per PETS (2 accelerating structures)0.21 m active lengthtotal number : 35’703 per linac

I. Syratchev

Page 22: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 23

Power Extraction Structures (PETS)

(Previously considered PETS a significant risk)

160

180

200

Pow

er [M

W]

12.0

5.09

TBTS PETS,140 ns flat,25 minutes.

135 MW (CLIC 3 TeV target)

153 MW (CLIC 0.5 TeV target)

266 ns 266 ns133 ns

150 Hours 210 Hours

PETS 1st run (winter 2008/09) PETS 2nd run (May 2009…)

F. Zimmermann

Page 23: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 24

CLIC Test Facility CTF3

Provide answers for CLIC specific issues Write CDR in 2010

Two main missions:

Prove CLIC RF power source scheme:• bunch manipulations, beam stability,• Drive Beam generation• 12 GHz extraction

Demonstration of “relevant” linac sub-unit:• acceleration of test beam

Provide RF power for validation of CLIC components: accelerating structures, RF distribution, PETS (Power extraction and Transfer Structure)

G. Geshonke

Page 24: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 25

CTF3 building blocks

150 MeV e-linac

PULSE COMPRESSIONFREQUENCY MULTIPLICATION

CLEX (CLIC Experimental Area)TWO BEAM TEST STAND

PROBE BEAMTest Beam Line

3.5 A - 1.4 s

28 A - 140 ns

30 GHz test stand

Delay LoopCombiner Ring

D FFD

D F DD F D D F D

D F D

DF DF DF DF DF DF DF DF DF

D F DF DF D

D FFFDD

D F DD F DD F DD F D D F DD F D

D F DD F D

DF DF DF DF DF DF DF DF DF DFDF DF DF DF DF DF DF DF DF DF DF DF DF DF DF DF

D F DD F DF DF DF DF D

total length about 140 m

magnetic chicane

10 m

Photo injector tests,laser

Infrastructure from LEP

G. Geshonke

Page 25: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 26

Delay Loop

circumference 42 m (140 ns)isochronous opticswiggler to tune path length (9 mm range)

1.5 GHz RF deflector

Designed and built by INFN Frascati

G. Geshonke

Page 26: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 28

Other R&D on performance issues

R&D on Damping Rings and Beam Deliveryin other test facilities:

CESR-TA at Cornell: Electron Cloud mitigation and low emittance tuning

ATF/ATF2 at KEK: Low emittance damping ringFinal focus test facility to demonstratenanometer beam sizes and stability

Page 27: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 29

Electron cloud mitigation R&D: PEP-II chicane

TiN surface much reduced signal with respect to Al

Observed new resonance: Electron current peaks at defined B values (n)

Test chamber Al and TiN-coated

New 4-dipole chicane in the PEP-II LER

Mitigation tests in ILC magnetic field

Aluminum surface

M. Pivi

Page 28: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 30

ILC Damping Ring R&D

Lattice design for baseline positron ringLattice design for baseline electron ringDemonstrate < 2 pm vertical emittanceCharacterize single bunch impedance-driven instabilitiesCharacterize electron cloud build-upDevelop electron cloud suppression techniquesDevelop modelling tools for electron cloud instabilitiesDetermine electron cloud instability thresholdsCharacterize ion effectsSpecify techniques for suppressing ion effectsDevelop a fast high-power pulser

11 very high priority R&D items to be addressed for the ILC technical design:

Targeted for CesrTAEffort with Low

Emittance e+ BeamTargeted for

ATF Effort

M. Palmer

Page 29: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 31

Model of ILC final focus

Beamline, January 2008 May 2008

Summer 2007

HA PS

FD integration

ATF2 goals :(A) Small beam size ~37nm(B) nm stability of beam center

ATF international collaboration: MOU signed by 20 institutions ATF2 constructed as ILC model, with in-kind contributions Start of beam commissioning: October 2008

ATF2

A. Seryi

Page 30: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 32

ILC – CLIC collaboration

CLIC ILC

Physics & Detectors L.Linssen, D.Schlatter F.Richard, S.Yamada

Beam Delivery System (BDS) & Machine Detector Interface (MDI)

D.Schulte, R.Tomas GarciaE.Tsesmelis

B.Parker, A.Seriy

Civil Engineering &Conventional Facilities

C.Hauviller, J.Osborne. J.Osborne,V.Kuchler

Positron Generation (new) L.Rinolfi J.Clarke

Damping Rings (new) Y.Papaphilipou M.Palmer

Beam Dynamics D.Schulte A.Latina, K.Kubo, N.Walker

Cost & Schedule P.Lebrun, K.Foraz, G.Riddone

J.Carwardine, P.Garbincius, T.Shidara

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2009 SLUO Meeting Sept 17, 2009 Page 33

GDE: ILC Timeline

Reference Design Report (RDR)GDE process

TDP 2

LHC physics

2005 2006 2007 2008 20122009 2010 2011 2013

Ready for Project Submission

Tech. Design Phase (TDP) 1

We are hereB. Barish

April 2009

Page 32: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 34

Tentative long-term CLIC scenarioShortest, Success Oriented, Technically Limited Schedule

Technology evaluation and Physics assessment based on LHC results for a possible decision on Linear Collider with staged construction

starting with the lowest energy required by Physics

First Beam?

TechnicalDesignReport(TDR)

ConceptualDesignReport(CDR)

Project approval ?

2007 2008 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023

R&D on Feasibility Issues

Conceptual Design

R&D on Performance and Cost issues

Technical design

Engineering Optimisation&Industrialisation

Construction (in stages)Construction Detector

2009

G. Geshonke

Page 33: Linear Collider – Next Steps in R&D

2009 SLUO Meeting Sept 17, 2009 Page 35

Summary

ILC: 500 GeV, upgradable to 1 TeV

Technology quite advanced. Much recent progress.

TDP plan to be ready for a proposal in 2013.

Key R&D: Cavity gradient, improved RF sources, electron cloud, BDS

CLIC: designed to reach 3 TeV, probably in stages

Still much R&D. CTF3 just coming on line.

TDR expected end 2015. Could be proposed in 2018?

Key R&D: Structure gradient & damping, PETS, drive beam generation, also sources, damping rings and BDS issues


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