• S.M. Pattalwar, R. Bate, R.K. Buckley, B.D. Fell, A.R. Goulden, P.A. McIntosh
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

The superconducting LINAC for the proposed New Light Source (NLS) project in the UK, will consist of 18 cryomodules operating at 1.8 K, each having 8, 1.3 GHz cavities operating in CW mode. The cryomodule design and cryogenic distribution scheme will be one of the key elements to achieve the desired performance from the superconducting RF (SRF) linac. Around the world, several large scale facilities (based on SRF linacs) are already operating (for example: CEBAF, SNS, FLASH) and several more have been proposed (XFEL, ILC, Cornell ERL, etc.). In this paper we define the requirements for an appropriate cryomodule, adopting proven L-band technology systems and also describe the cryogenic distribution scheme, in order to develop an effective and economic solution for the NLS.

• P.A. McIntosh, A.R. Goulden, A.J. Moss, S.M. Pattalwar, A.E. Wheelhouse
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

A design optimisation has been performed for an L-band, SRF linac adopting cryomodule technology developed as part of the TESLA Technology Collaboration (TTC). A conventional XFEL cryomodule has been adopted as a baseline design and modified to allow for CW operation at a nominally high Qo level. An assessment of appropriate operating gradient, based upon expected sub-system component costs and SRF linac operating costs, has been performed. The associated cryomodule modifications to accommodate such a large dynamic load are also highlighted, along with identifying an appropriate RF control architecture which can achieve the stringent phase and amplitude stability requirements for NLS.

• Y.M. Saveliev, R. Bate, R.K. Buckley, S.R. Buckley, J.A. Clarke, P.A. Corlett, D.J. Dunning, A.R. Goulden, S.F. Hill, F. Jackson, S.P. Jamison, J.K. Jones, L.B. Jones, S. Leonard, 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, D.J. Scott, E.A. Seddon, B.J.A. Shepherd, S.L. Smith, N. Thompson, A.E. Wheelhouse, P.H. Williams
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• P. Harrison, D.J. Holder, G.M. Holder, A.L. Schofield, P. Weightman, R.L. Williams
  The University of Liverpool, Liverpool
• D. Laundy
  STFC/DL, Daresbury, Warrington, Cheshire
• T. Powers
  JLAB, Newport News, Virginia
• G. Priebe, M. Surman
  STFC/DL/SRD, Daresbury, Warrington, Cheshire

Progress made in ALICE (Accelerators and Lasers In Combined Experiments) commissioning and a summary of the latest experimental results are presented in this paper. After an extensive work on beam loading effects in SC RF linac (booster) and linac cavities conditioning, ALICE can now operate in full energy recovery mode at the bunch charge of 40pC, the beam energy of 30MeV and train lengths of up to 100us. This improved operation of the machine resulted in generation of coherently enhanced broadband THz radiation with the energy of several tens of uJ per pulse and in successful demonstration of the Compton Backscattering x-ray source experiment. The next steps in the ALICE scientific programme are commissioning of the IR FEL and start of the research on the first non-scaling FFAG accelerator EMMA. Results from both projects will be also reported.

• A.R. Goulden, R. Bate, R.K. Buckley, P.A. McIntosh, S.M. Pattalwar
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

The proposed New Light Source (NLS) based on a CW superconducting linear accelerator requires large scale cryogenic refrigeration equipment comparable to some of largest installations around the world (for example CEBAF/SNS and LHC). The maximum refrigeration power requirement is estimated to be 3.4 kW at 1.8 K. The ratio of the dynamic to the static heat load is in excess of 20 and handling such large variations in the refrigeration power is the key issue in the development of the cryogenic system for NLS. In this paper we present our approach to address the issues relating to efficient and reliable operability, operational functionality and capital costs, in order to develop an effective and economic solution for NLS.