• 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.

• 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

• D.J. Scott, S.P. Jamison
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• P.J. Phillips
  University of Dundee, Nethergate, Dundee, Scotland
• I.R.R. Shinton
  UMAN, Manchester

Accurate determination of the wakefield effects for high intensity, short electron bunches is an area of active research in accelerator design. Of particular interest is the resistive wall wakefield which depends upon the complex conductivity of the vacuum vessel. This conductivity depends on factors such as the frequency of the applied field, the temperature of the vessel and the level of impurities in the vessel material and so is generally difficult to characterise for real vessels. We present an experiment for determining the complex conductivity properties of a cylindrical vessel at frequencies in the THz regime, through the sub-picosecond time-resolved measurement of pulsed THz radiation transmitted through the structure. These results are compared to theoretical calculations.