Bunch Frequency Multiplicationin the

CLIC Test Facility CTF 3

R. Corsini, L. Rinolfi, F. Tecker – CERN, SwitzerlandC. Biscari, A. Ghigo, M. Preger– INFN, Italy

P. Royer– Lausanne University, SwitzerlandA. Ferrari – Uppsala University, Sweden

Introduction to CTF 3

Bunch Frequency Multiplication

Bunch Combination Results

Conclusions

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

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Introduction to CTF 3

CLIC: CompactLI near Collider (0.5–5 TeV)

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two beamacceleration scheme:

high charge, low energydrive beam(2 GeV)

produce RF power athigh frequency – 30 GHz

high gradient – 150 MV/m

low charge,high energy main beam(1.5 TeV)

CLIC TestFacility 3 addressesfeasibility issues:test ofdrive beam generation

combination of bunches byRF deflectors⇒ bunch frequency multiplication

RF power production at 30 GHz

test CLIC components

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

http://cern.ch/ctf3http://cern.ch/ctf3http://www.cern.chhttp://ps-div.web.cern.ch/ps-div/CLIC/Welcome.htmlhttp://ps-div.web.cern.ch/ps-div/CLIC/Welcome.htmlhttp://cern.ch/teckerhttp://ps-div.web.cern.ch/ps-div/CLIC/Welcome.htmlhttp://cern.ch/ctf3http://www-conf.slac.stanford.edu/pac03/

Frequency multiplication

basic principle of drive beam generation

transform very long pulses into many shortpulses withhigher power and higher frequency

useRF deflectorsto interleavebunches

⇒ double beam power⇒ double beam frequency

CTF3 deflector, INFN

CTF3 deflector, CERN

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

http://cern.ch/ctf3http://www.cern.chhttp://cern.ch/teckerhttp://ps-div.web.cern.ch/ps-div/CLIC/Welcome.htmlhttp://cern.ch/ctf3http://www-conf.slac.stanford.edu/pac03/

Preliminary phase of CTF 3 (2001–2002)

gun & bunchingsystem

Linac ( 8 structures )

matchingsection

isochronousinjection line

RF deflectors

streak camerameasurement

isochronous ring

total Length 1.7 µs - av. Pulse Current 0.3 A

Bunch spacing10 cm (333 ps)6.6 ns 420 ns

Pulse Length 6.6 nsav. Pulse Current 1.5 A

Bunch spacing 2 cm (67 ps)

Beam structurein linac

(up to 100 Hz)

Beam structureafter combination

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

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Combination by RF deflectors in a ringC L I CC L I C

Four-Turn Ring InjectionFour-Turn Ring Injection

3rd

1st turn

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injectionline

transverse deflector

field

localinner orbits

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deflector 2���

deflector

septum

4rd

• Want a factor 4 pulse compression &frequency multiplication

• Use transverse RF deflectorinjection in a ring

Bunch train combination by RF deflectors

Basic principle of bunch train combination by RF deflector injection in an isochronous ring

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Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

http://cern.ch/ctf3http://www.cern.chhttp://cern.ch/teckerhttp://ps-div.web.cern.ch/ps-div/CLIC/Welcome.htmlhttp://cern.ch/ctf3http://www-conf.slac.stanford.edu/pac03/

CTF3 recombination factor 4 - 1 pulse

time

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

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CTF3 recombination factor 4 - 2 pulses

time

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

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CTF3 recombination factor 4 - 3 pulses

time

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

http://cern.ch/ctf3http://www.cern.chhttp://cern.ch/teckerhttp://ps-div.web.cern.ch/ps-div/CLIC/Welcome.htmlhttp://cern.ch/ctf3http://www-conf.slac.stanford.edu/pac03/

CTF3 recombination factor 4 - 4 pulses

time

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

http://cern.ch/ctf3http://www.cern.chhttp://cern.ch/teckerhttp://ps-div.web.cern.ch/ps-div/CLIC/Welcome.htmlhttp://cern.ch/ctf3http://www-conf.slac.stanford.edu/pac03/

Recombination factor 4 - beam current

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

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CTF3 recombination factor 5

5 cm)(2nruht5

o = 0 mc

t

λ 1

/oλ

bunch distance 333 ps→ 67 psfrequency 3 GHz→ 15 GHz

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

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Conclusions

CTF 3 preliminary phase

bunch frequency multiplication by RF deflectorsdemonstratedfor factors 2 – 5 at low charge

crucial step for the CLIC study

CTF 3 initial phase

drive beam linac is being installed now (higher charge)

commissioning starts this month

Acknowledgements:

R. Corsini, A. Ferrari, L. Rinolfi, P. Royer

various CERN divisions and groups

Collaborations:INFN, Frascati, Italy – SLAC, USA – RAL, UK –IN2P3-LAL, France – Uppsala University, Sweden

Frank Tecker Bunch Frequency Multiplication in the CLIC Test Facility CTF 3 PAC 2003, 15.5.2003

http://cern.ch/ctf3http://www.cern.chhttp://cern.ch/teckerhttp://ps-div.web.cern.ch/ps-div/CLIC/Welcome.htmlhttp://cern.ch/ctf3http://www-conf.slac.stanford.edu/pac03/