CLIC OverviewCLIC Overview

Andrea Latina (APC/FNAL)for the CLIC/CTF3 Collaboration

June 10, 2009 - Low Emittance Muon Collider Workshop, FNALJune 10, 2009 - Low Emittance Muon Collider Workshop, FNAL

OutlineOutline

• Introduction– Physics Case– Linear Colliders

• CLIC– Introduction and main challenges– The two beam accelerator scheme– CLIC technological issues

• CTF3 – CLIC Test Facility– Recent achievements

• Summary

High Energy Physics after LHCHigh Energy Physics after LHC

ICFA: International Commitee for Future Accelerators

Linear Collider e+e- Physics

• Higgs physics– Tevatron/LHC should discover Higgs

(or something else)– LC explores its properties in detail

• Supersymmetry– LC will complement the LHC

particle spectrum• Extra spatial dimensions• New strong interactions

• . . . => a lot of new territory to discoverbeyond the standard model

• Energy can be crucial for discovery

• “Physics at the CLIC Multi-TeV Linear Collider”CERN-2004-005

• “ILC Reference Design Report – Vol.2 – Physics at the ILC” www.linearcollider.org/rdr

Linear versus Circular Colliders Linear versus Circular Colliders

Storage Rings• Acceleration+collision every

turn• “re-use” RF• “re-use” particles efficient Synchrotron Radiation Losses

Luminosity Event rate

Linear Collider• One-pass acceleration+collision• RF used only once• Particles dumped at each

collision need high acceleration gradient need small beam sizes at IP

~40 MHz ~10 Hz

m2 nm2

nb = bunches/trainN = particles per bunchfrep = repetition frequencyx,y = sizes of the beam at IPHD = beam-beam enhancement factor

~1034 cm-2 s-1

Main Challenges for a LC

• High Ecm : long linac / high gradients• nanometer beam sizes at the Interaction Point• Small emittance generation and preservation • Stabilization and Final Focusing

11stst challenge: H challenge: High Gradientsigh Gradients

• Super conducting SW cavities : high efficiency, long pulse, gradient ~35 MV/m, but long filling time

• Normal conducting cavities : high gradients (with traveling wave structures), high frequency, short filling time, short pulse

RF ‘flows’ with group velocity vG along the structure into a load at the structure exit

pulsed RFPowersource

dRF load

Main linac

22ndnd challenge: interaction point beam sizes challenge: interaction point beam sizes

(picture from A. Seryi, ILC@SLAC)(picture from A. Seryi, ILC@SLAC)

(values for CLIC, 11/2008(values for CLIC, 11/2008

Vertical size is smallest

Dyx

brepH

NnfL

2

4

1

4400045

In order to maximize the luminosity we need very small beam sizes at the interaction point and a flat beam

))

IP

33ndnd challenge: emittance challenge: emittance

Key concept in linear colliders: Generation and preservation of very small emittance!

Generation of small emittances: synchrotron radiation damping -> damping rings

Preservation of small emittances: precision alignment and steering, limitation of collective effects (synchrotron radiation, wake fields)

)()( ss rms

Beam quality

Lattice

RMS beam sizeRMS beam size

RTMLMain linacBeam Delivery

Damping Rings

Source

CLIC: Compact Linear ColliderCLIC: Compact Linear Collider

Centre of mass energy 3 TeV

Luminosity (in 1% energy) 2x1034 cm-2 s-1

Repetition rate 50 Hz

Loaded accelerating gradient 100 MV/m

Main linac RF frequency 12 GHz

Overall two-linac length 41.7 km

Bunch charge 4·109

Beam pulse length 240 ns

Average current in pulse 1 A

Hor./vert. normalized emittance 660 / 20 nm rad

Hor./vert. IP beam size before pinch 45 / ~1 nm

Total site length 48.25 km

Total power consumption 400 MW

Key parameters:

Goals of the study:

CLIC at different energiesCLIC at different energies

3 TeV Stage

Linac 1 Linac 2

Injector Complex

I.P.

3 km20.8 km 20.8 km 3 km

48.2 km

Linac 1 Linac 2

Injector Complex

I.P.

7.0 km 7.0 km

1 TeV Stage

0.5 TeV StageLinac 1 Linac 2

Injector Complex

I.P.

4 km

~14 km

4 km

~20 km

CLIC schematic layout @ 3 TeVCLIC schematic layout @ 3 TeV

Drive beam

The CLIC Two-Beam AcceleratorThe CLIC Two-Beam Accelerator

main beam 1 A, 156 ns9 GeV - 1.5 TeV

DRIVE BEAM

PROBE

BEAM

Why a two-beam scheme?Why a two-beam scheme?

• Luminosity scales as wall-plug-to-beam efficiency. Need to obtain: high-gradient acceleration and efficient energy transfer.

• High-frequency RF maximizes the electric field in the RF cavities for a given stored energy.

• However, standard RF sources scale unfavorably to high frequencies, both in for maximum delivered power and efficiency.

• A way to overcome such a drawback is to use standard low-frequency RF sources to accelerate the drive beam and then use it to produce RF power at high frequency.

• The drive beam is therefore used for intermediate energy storage.

Dyx

repb HfNn

L**

2

4

Dyx

AC HNP**

Luminosity

Drive Beam IdeaDrive Beam Idea

• Very high gradients possible with NC accelerating structures at high RF frequencies (30 GHz → 12 GHz)

• Extract required high RF power from an intense e- “drive beam”• Generate efficiently long beam pulse and

compress it (in power + frequency)

Long RF PulsesP0 , 0 , 0

Short RF PulsesPA = P0 N1

A = 0 / N2 A = 0 N3

Electron beam manipulation

Power compressionFrequency multiplication

‘few’ KlystronsLow frequencyHigh efficiency

Accelerating StructuresHigh Frequency – High field

Power stored inelectron beam

Power extracted from beamin resonant structures

Two Beams schemeTwo Beams scheme

CLIC acceleration systemCLIC acceleration system

Why 100 MV/m at 12 GHz?Why 100 MV/m at 12 GHz?

Accelerating structuresAccelerating structures

Best Result so far..Best Result so far..

Power Extraction Transfer Structures - Power Extraction Transfer Structures - PETSPETS

CLIC Accelerating ModuleCLIC Accelerating Module

Getting the Luminosity (>2 x10Getting the Luminosity (>2 x103434 cm cm-2-2ss-1-1))

Low emittance generationLow emittance generation

Many other issues besides intra-beam scattering : fast-ion instability and e-cloud (being mitigated using different coating for the vacuum chamber, tests at CESR-TA summer 2009), wiggler design..

Damping Ring EmittancesDamping Ring Emittances

Rings to Main LinacRings to Main Linac

RTML includes:

•BC1 stage: bunch length from 5 mm to 1.5 mm at 2.4 GeV

•Booster linac from 2.4 to 9 GeV

•Transfer line and turnaround loops

•BC2 stage: from 1.5 mm to 44 microm

=> max 5 nm vertical emittance growth is allowed

First partcle tracking through the complete system

20 km

boos

ter

Emittance Preservation in the Main LinacEmittance Preservation in the Main Linac

Vertical emittance growth bugdet is 10 nm

Emittance Preservation in the MLEmittance Preservation in the ML

Example for cavity misalignmentExample for cavity misalignment

Static Imperfections in the MLStatic Imperfections in the ML

Beam Delivery SystemBeam Delivery System

Optics design for the 3 TeV option (alternative design for 0.5 TeV exists)

Interaction Region

Final Focus QD0 StabilizationFinal Focus QD0 Stabilization

QD0 must be stabilized to 0.15 nm for frequencies above 4 Hz

Active Stabilization StudiesActive Stabilization Studies

0.13 nm have been reached in laboratory, the challenge remains to prove 0.15 nm within the detector

B. B

olz

on,

L. B

run

ett

i, N

. G

eff

roy a

nd

A. Je

rem

ie

Conceptual Design Report (CDR) - end 2010Conceptual Design Report (CDR) - end 2010

The CLIC CDR should address the critical points:

• Accelerating structures at 100 MV/m

• Power Extraction and Transfer Structures (PETS)

• Generation of the 100 A drive beam with 12 GHz bunch frequency

• meeting the phase, energy and intensity stability tolerances

• Main beam low emittances

• Stabilization of main quads. to 1nm and FD quads to 0.15nm (freqs>4 Hz)

• Machine protection issues

=> Test facilities at CERN: CTF3 / CLEX

CTF3: Drive Beam Test-BenchCTF3: Drive Beam Test-Bench

Drive beam

CLIC R&D issues: CTF3/CLEXCLIC R&D issues: CTF3/CLEX

CTF3 is a small scale version of the CLIC drive beam complex: Provide the RF power to test the CLIC accelerating structures and components Full beam-loading accelerator operation Electron beam pulse compression and frequency multiplication Safe and stable beam deceleration and power extraction High power two beam acceleration scheme

Current Status of CTF3Current Status of CTF3

39EPAC 2008 CLIC / CTF3 G.Geschonke, CERN

existing building

D FFD

D F D

D F D D F D

D F D

DF DF DF DF DF DF DF DF DF

D F D

F DF D

D FFFDD

D F DD F D

D 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 D

F DF DF DF D

42.5 m

8 m

2m

D FFD

D F DDUMPD F D

ITB

1.85m

CALIFES Probe beam injector

LIL-ACSLIL-ACSLIL-ACSD F D

D F D

DFDUMP

0.75

1.4m

1

DUMP

22.4 mTBL

2.5m

Transport path

22 m

2.0m

DF DF DF DF DF DF DF DF

3.0m3.0m6 m

D F D

F DF D

16.5 mTBTS

16 m

TL2’

42.5 m42.5 m

8 m

8 m

2m2m

D FFFDD

D F DD F DDUMPD F DD F D

ITB

1.85m1.85m

CALIFES Probe beam injector

LIL-ACSLIL-ACSLIL-ACSLIL-ACSLIL-ACSLIL-ACSD F DD F D

D F DD F D

DF DFDUMP

0.75

1.4m1.4m

11

DUMP

22.4 m22.4 mTBL

2.5m2.5m

Transport path

22 m22 m

2.0m2.0m

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

3.0m3.0m3.0m3.0m6 m6 m

D F DD F D

F DF DF DF D

16.5 m16.5 mTBTS

16 m16 m

TL2’

Test Beam Line TBL

CLEX building

Jan 2008

Jan 2008

September 2006June 2006

June 2008

Probe Beam linac

June 2008Two Beam Test Stand

(University Uppsala)

Equipment installed (except TBL),Beam foreseen from June 2008

CTF3: full beam loadingCTF3: full beam loading

Delay LoopDelay Loop

Combiner RingsCombiner Rings

CTF3: x 4 combination in CRCTF3: x 4 combination in CR

CTF3: Power Extraction and RecirculationCTF3: Power Extraction and Recirculation

•The first 12 GHz PETS was tested with BEAM in November and December last year•Recirculation of the output field was used, to produce more power from the 5A CTF3 current•30 MW of RF power were generated (plot shows 25 MW)•RF signal was reproduced using BPM intensity signal

PETS shows excellent behaviour and agreed with design performanceThis also means that the this is a very good test-bench to test PETS in two-beam acceleration

SummarySummary

•Excellent progress towards the CLIC CDR (2010)

•Technical program is on track

• but lots of work still to be done.

• Challenging work and tight schedule!

LHC results

The CTF3 – CLIC world wide collaboration

46EPAC 2008 CLIC / CTF3 G.Geschonke, CERN

Helsinki Institute of Physics (Finland) IAP (Russia)IAP NASU (Ukraine)Instituto de Fisica Corpuscular (Spain)INFN / LNF (Italy)J.Adams Institute, (UK)JINR (Russia)

Oslo University (Norway)PSI (Switzerland),Polytech. University of Catalonia

(Spain)RRCAT-Indore (India)Royal Holloway, Univ. London, (UK) SLAC (USA)Uppsala University (Sweden)

Ankara University (Turkey)BINP (Russia)CERNCIEMAT (Spain)Cockcroft Institute (UK)Gazi Universities (Turkey)IRFU/Saclay (France)

JLAB (USA)Karlsruhe University (Germany)KEK (Japan) LAL/Orsay (France) LAPP/ESIA (France)NCP (Pakistan)North-West. Univ. Illinois (USA)

28 institutes involving 18 funding agencies from 16 countries