• M.P. Anania, D. Clark, R.C. Issac, D.A. Jaroszynski, A. J. W. Reitsma, G.H. Welsh, S.M. Wiggins
  USTRAT/SUPA, Glasgow
• J.A. Clarke, M.W. Poole, B.J.A. Shepherd
  Cockcroft Institute, Warrington, Cheshire
• M.J. de Loos, S.B. van der Geer
  Pulsar Physics, Eindhoven

Funding: The U.K. EPSRC and the European Community - New and Emerging Science and Technology Activity under the FP6 “Structuring the European Research Area” programme (project EuroLEAP, contract number 028514)

The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme* is developing laser-plasma accelerators for the production of ultra-short electron bunches as drivers of incoherent and coherent radiation sources from plasma and magnetic undulators. Focusing of ultra-short electron bunches from a laser-plasma wakefield accelerator into an undulator requires that particular attention be paid to the electron beam quality. We will discuss the design and implementation of an upgraded focusing system for the ALPHA-X beam line, which currently consists of a triplet of electromagnet quadrupoles. The upgrade will comprise the installation of additional compact permanent quadrupoles** very close to the accelerator exit. This will improve the matching of the beam into the undulator. The design has been carried out using the General Particle Tracer (GPT) code*** and TRANSPORT code, which consider space charge effects and allow a realistic estimate of electron beam properties inside the undulator to be obtained. We will present a study of the influence of beam transport on free-electron laser action in the undulator, paying particular attention to bunch dispersion.

* D. Jaroszynski et al., Phil. Trans. R. Soc. A 364, 689-710 (2006)
** T. Eichner et al., Phys. Rev. ST Accel. Beams 10, 082401 (2007)
*** S.B. Geer, M.J. Loos, Ph.D. thesis, TU/e, Eindhoven (2001)

Slides

• R.P. Walker, R. Bartolini, C. Christou, J.H. Han, J. Kay, I.P.S. Martin, G. Rehm, J. Rowland
  Diamond, Oxfordshire
• D. Angal-Kalinin, M.A. Bowler, J.A. Clarke, D.J. Dunning, B.D. Fell, A.R. Goulden, F. Jackson, S.P. Jamison, J.K. Jones, K.B. Marinov, P.A. McIntosh, J.W. McKenzie, B.L. Militsyn, A.J. Moss, B.D. Muratori, S.M. Pattalwar, M.W. Poole, R.J. Smith, S.L. Smith, N. Thompson, P.H. Williams
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• N. Bliss, G.P. Diakun, M.D. Roper
  STFC/DL, Daresbury, Warrington, Cheshire
• J.L. Collier, C.A. Froud, G.J. Hirst, E. Springate
  STFC/RAL, Chilton, Didcot, Oxon
• J.P. Marangos, J.W.G. Tisch
  Imperial College of Science and Technology, Department of Physics, London
• B.W.J. McNeil
  USTRAT/SUPA, Glasgow
• H.L. Owen
  UMAN, Manchester

The New Light Source (NLS) project was launched in April 2008 by the UK Science and Technology Facilities Council (STFC) to consider the scientific case and develop a conceptual design for a possible next generation light source based on a combination of advanced conventional laser and free-electron laser sources. Following a series of workshops and a period of scientific consultation, the science case was approved in October 2008 and the go-ahead given to continue the project to the design stage. In November the decision was taken that the facility will be based on cw superconducting technology in order to provide the best match to the scientific objectives. In this paper we present the source requirements, both for baseline operation and with possible upgrades, and the current status of the design of the accelerator driver and free-electron laser sources to meet those requirements.

• J. Rochford
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• I.R. Bailey
  Lancaster University, Lancaster
• E. Baynham, T.W. Bradshaw, A.J. Brummitt, D.A. Burton, F.S. Carr, A.J. Lintern
  STFC/RAL, Chilton, Didcot, Oxon
• J.A. Clarke, O.B. Malyshev, D.J. Scott, B.J.A. Shepherd
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• Y. Ivanyushenkov
  ANL, Argonne
• G.A. Moortgat-Pick
  Durham University, Durham
• N.C. Ryder
  University of Bristol, Bristol

The ILC positron source relies upon a ~200 m long superconducting helical undulator in order to generate the huge flux of gamma photons required. The period is only 11.5 mm but the field strength is ~1 T. The UK is building and testing a full scale 4 m long ILC cryomodule at the moment. It will be completed in 2008 and the results used to demonstrate the feasibility of the full (200 m long) system.

Slides

• L. Rinolfi, F. Antoniou, H.-H. Braun, Y. Papaphilippou, D. Schulte, A. Vivoli, F. Zimmermann
  CERN, Geneva
• E.V. Bulyak, P. Gladkikh
  NSC/KIPT, Kharkov
• R. Chehab
  IN2P3 IPNL, Villeurbanne
• J.A. Clarke
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• O. Dadoun, P. Lepercq, R. Roux, A. Variola, Z.F. Zomer
  LAL, Orsay
• W. Gai, W. Liu
  ANL, Argonne
• T. Kamitani, T. Omori, J. Urakawa
  KEK, Ibaraki
• M. Kuriki
  HU/AdSM, Higashi-Hiroshima
• I. Pogorelsky, V. Yakimenko
  BNL, Upton, Long Island, New York
• T. Takahashi
  Hiroshima University, Graduate School of Science, Higashi-Hiroshima

The CLIC polarized positron source is based on a positron production scheme in which polarized photons are produced by Compton process. Compton backscattering happens in a so-called "Compton ring" where an electron beam of 1.06 GeV interacts with a powerful laser beam amplified in an optical resonator. The circularly-polarized gamma rays are sent on to a target, producing pairs of longitudinally polarized electrons and positrons. An Adiabatic Matching Device maximizes the capture of the positrons. A normal-conducting 2 GHz Linac accelerates the beam up to 2.424 GeV before injection into the Pre-Damping Ring (PDR). The nominal CLIC bunch population is 4.4x10⁹ particles per bunch. Since the photon flux coming out from a "Compton ring" is not sufficient to obtain the requested charge, a stacking process is required in the PDR. Another option is to use a "Compton Energy Recovery Linac" where a quasi-continual stacking in the PDR could be achieved. A third option is to use a "Compton Linac" which would not require stacking. We describe the overall scheme as well as advantages and constraints of the three different options.

• S.L. Smith, R. Bate, C.D. Beard, M.A. Bowler, R.K. Buckley, S.R. Buckley, J.A. Clarke, P.A. Corlett, M. Dufau, D.J. Dunning, B.D. Fell, P. Goudket, A.R. Goulden, S.A. Griffiths, J.D. Herbert, C. Hill, F. Jackson, S.P. Jamison, J.K. Jones, L.B. Jones, A. Kalinin, N. Marks, P.A. McIntosh, J.W. McKenzie, K.J. Middleman, B.L. Militsyn, A.J. Moss, B.D. Muratori, J.F. Orrett, S.M. Pattalwar, P.J. Phillips, M.W. Poole, Y.M. Saveliev, D.J. Scott, B.J.A. Shepherd, R.J. Smith, N. Thompson, B. Todd, T.M. Weston, A.E. Wheelhouse, P.H. Williams
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• J.R. Alexander, P. Atkinson, N. Bliss, I. Burrows, G. Cox, P.A.D. Dickenson, A. Gallagher, K.D. Gleave, J.P. Hindley, B.G. Martlew, I.D. Mullacrane, A. Oates, P.D. Quinn, D.G. Stokes, J. Strachan, P.J. Warburton, C.J. White
  STFC/DL, Daresbury, Warrington, Cheshire
• W.R. Flavell, E.A. Seddon
  UMAN, Manchester
• F.G. Gabriel
  FZD, Dresden
• C. Gerth
  DESY, Hamburg
• F.E. Hannon, C. Hernandez-Garcia, K. Jordan, G. Neil
  JLAB, Newport News, Virginia
• K. Harada
  KEK, Ibaraki
• P. Harrison, D.J. Holder, G.M. Holder, P. Weightman
  The University of Liverpool, Liverpool
• S.F. Hill, G. Priebe, R.V. Rotheroe, M. Surman
  STFC/DL/SRD, Daresbury, Warrington, Cheshire
• G.J. Hirst, P.G. Huggard
  STFC/RAL, Chilton, Didcot, Oxon
• P. vom Stein
  ACCEL, Bergisch Gladbach

ALICE (Accelerators and Lasers in Combined Experiments) is a 35 MeV energy recovery linac based light source. ALICE is being developed as an experimental test-bed for a broad suite of science and technology activities that make use of electron acceleration and ultra-short pulse laser techniques. This paper reports the progress made in accelerator commissioning and includes the results of measurement made on the commissioning beam. The steps taken to prepare the beam for short pulse operation as a driver for a Compton Back Scattered source and in preparation for the commissioning of the free electron laser are reported.