Author: Andersson, A.
Paper Title Page
MOPME077 Electro-0ptical Bunch Profile Measurement at CTF3 658
 
  • R. Pan, A. Andersson, W. Farabolini, A. Goldblatt, T. Lefèvre, M. Martyanov, S. Mazzoni, S.F. Rey, L. Timeo
    CERN, Geneva, Switzerland
  • W.A. Gillespie, R. Pan, D.A. Walsh
    University of Dundee, Nethergate, Dundee, Scotland, United Kingdom
  • S.P. Jamison
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  
  A new elec­tro-op­tic bunch pro­file mon­i­tor has re­cently been in­stalled in CLIC Test Fa­cil­ity 3 at CERN. The mon­i­tor is based on an elec­tro-op­tic spec­tral de­cod­ing scheme which re­con­structs the lon­gi­tu­di­nal pro­file of the elec­tron bunch by mea­sur­ing its Coulomb field. The sys­tem uses a 780 nm fibre laser sys­tem, trans­ported over a 20m long dis­tance to the in­ter­ac­tion cham­ber, where a ZnTe crys­tal is po­si­tioned close to the beam. The as­sem­bly also con­tains a tra­di­tional OTR screen, which is cou­pled to a sec­ond op­ti­cal line and used to ad­just the tem­po­ral over­lap be­tween the laser and the elec­tron pulse. This paper pre­sents the de­tec­tion sys­tem in de­tail, as well as re­port­ing on the first mea­sure­ments per­formed with beam.  
 
TUPFI040 Experimental Verification of the CLIC Two-Beam Acceleration Technology in CTF3 1436
 
  • P. Skowroński, A. Andersson, J. Barranco, B. Constance, R. Corsini, S. Döbert, A. Dubrovskiy, W. Farabolini, E. Ikarios, R.L. Lillestøl, T. Persson, F. Tecker
    CERN, Geneva, Switzerland
  • W. Farabolini
    CEA/DSM/IRFU, France
  • E. Ikarios
    National Technical University of Athens, Athens, Greece
  • M. Jacewicz, A. Palaia, R.J.M.Y. Ruber
    Uppsala University, Uppsala, Sweden
  • R.L. Lillestøl
    University of Oslo, Oslo, Norway
  • T. Persson
    Chalmers University of Technology, Chalmers Tekniska Högskola, Gothenburg, Sweden
  
  The Com­pact Lin­ear Col­lider (CLIC) In­ter­na­tional Col­lab­o­ra­tion is pur­su­ing an ex­ten­sive R&D pro­gram to­wards a multi-TeV elec­tron-positron col­lider. In par­tic­u­lar, the de­vel­op­ment of two beam ac­cel­er­a­tion tech­nol­ogy is the focus of the CLIC test fa­cil­ity CTF3. In this paper we sum­ma­rize the most re­cent re­sults ob­tained at CTF3: the re­sults of the stud­ies on the drive beam gen­er­a­tion are pre­sented, the achieved two beam ac­cel­er­a­tion per­for­mance is re­ported and the mea­sured break-down rates and re­lated ob­ser­va­tions are sum­ma­rized. The sta­bil­ity of de­cel­er­a­tion process per­formed over 13 sub­se­quent mod­ules and the com­par­i­son of the ob­tained re­sults with the the­o­ret­i­cal ex­pec­ta­tions are dis­cussed. We also out­line and dis­cuss the fu­ture ex­per­i­men­tal pro­gram.  
 
TUPME039 The Drive Beam Phase Stability in CTF3 and its Relation to the Bunch Compression Factor 1655
 
  • E. Ikarios, A. Andersson, J. Barranco, B. Constance, R. Corsini, A. Gerbershagen, T. Persson, P. Skowroński, F. Tecker
    CERN, Geneva, Switzerland
  
  The pro­posed Com­pact Lin­ear Col­lider (CLIC) is based on a two-beam ac­cel­er­a­tion scheme. The en­ergy needed to ac­cel­er­ate a low in­ten­sity "main" beam is pro­vided by a high in­ten­sity, low en­ergy "drive" beam. The pre­ci­sion and sta­bil­ity of the phase re­la­tion be­tween two beams is cru­cial for the per­for­mance of the scheme. The tol­er­a­ble phase jit­ter is 0.2 deg rms at 12GHz. For this rea­son it is fun­da­men­tal to un­der­stand the main pos­si­ble causes of the drive beam tim­ing jit­ter. Ex­per­i­men­tal work aimed at such un­der­stand­ing was done in the CLIC Test Fa­cil­ity (CTF3) where a drive beam with char­ac­ter­is­tics sim­i­lar to the CLIC one is pro­duced. Sev­eral phase mea­sure­ments al­lowed us to con­clude that the main source of phase jit­ter is en­ergy jit­ter of the beam trans­formed and am­pli­fied into phase jit­ter when pass­ing through a mag­netic chi­cane. This con­clu­sion is sup­ported by mea­sure­ments done with dif­fer­ent mo­men­tum com­paction val­ues in the chi­cane. In this paper the re­sults of these sev­eral phase mea­sure­ments will be pre­sented and com­pared with ex­pec­ta­tions.  
 
WEOBB203 Design of Phase Feed Forward System in CTF3 and Performance of Fast Beam Phase Monitors 2097
 
  • P. Skowroński, A. Andersson, A. Gerbershagen, E. Ikarios, J. Roberts
    CERN, Geneva, Switzerland
  • P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry, J. Roberts
    JAI, Oxford, United Kingdom
  • P. Burrows, G.B. Christian, A. Gerbershagen, C. Perry
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • A. Ghigo, F. Marcellini
    INFN/LNF, Frascati (Roma), Italy
  • E. Ikarios
    National Technical University of Athens, Athens, Greece
  
  Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579
The CLIC two beam ac­cel­er­a­tion tech­nol­ogy re­quires a drive beam phase sta­bil­ity of bet­ter than 0.3 deg rms at 12 GHz, cor­re­spond­ing to a tim­ing sta­bil­ity below 50 fs rms. For this rea­son the CLIC de­sign in­cludes a phase sta­bi­liza­tion feed-for­ward sys­tem. It re­lies on pre­cise beam phase mea­sure­ment and its sub­se­quent cor­rec­tion in a chi­cane with help of fast kick­ers. A pro­to­type of such a sys­tem is being in­stalled in CLIC Test Fa­cil­ity CTF3. In this paper we de­scribe in de­tail its de­sign and im­ple­men­ta­tion. Ad­di­tion­ally, we pre­sent and dis­cuss the per­for­mance of the pre­ci­sion phase mon­i­tor pro­to­types in­stalled at the end of the CTF3 linac, mea­sured with the drive beam.
We would like to acknowledge support of G.Sensolini, A.Zolla (INFN/LNF Frascati), N.S.Chritin and J-M.Scigliuto (CERN) in design and fabrication of components. 		 
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