• P.H. Williams, D.J. Dunning, N. Thompson
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• D. Angal-Kalinin, J.K. Jones, P.H. Williams
  Cockcroft Institute, Warrington, Cheshire
• R. Bartolini, I.P.S. Martin
  JAI, Oxford
• J. Rowland
  Diamond, Oxfordshire

We present progress in the design of the recirculating linac option for the UK New Light Source. Improvements in all accelerator sections have been made such that the output meets the required specifications to drive the seeded NLS FELs. Full start-to-end simulations and tolerance studies are presented together with a comparison to the baseline, single pass linac design.

• D. Angal-Kalinin, P.H. Williams
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• D. Angal-Kalinin, F. Jackson, S.P. Jamison, J.K. Jones, B.D. Muratori, N. Thompson
  Cockcroft Institute, Warrington, Cheshire
• R. Bartolini, I.P.S. Martin
  JAI, Oxford

The design of free electron laser (FEL) driver needs careful beam transport design to pass very short bunches through the switchyard/spreader to switch the beam to different FEL lines. The spreader design which allows flexibility in operation has been adapted following the LBNL design*. In order to measure the slice properties of the bunches two beam diagnostics lines are proposed, a straight one for beam commissioning purposes and a branch of the spreader similar to the FEL lines to measure the adverse effects that may arise due to passing the short bunches through the kicker and septum magnets. As a part of machine protection, post linac collimation system collimates the halo particles in transverse and energy planes. The design of the collimation, beam spreader and beam diagnostics lines is discussed.

* Zholents A.A. et al, CBP Tech Note 401, 2009

• M.A. Palmer, J.P. Alexander, M.G. Billing, J.R. Calvey, C.J. Conolly, J.A. Crittenden, J. Dobbins, G. Dugan, N. Eggert, E. Fontes, M.J. Forster, R.E. Gallagher, S.W. Gray, S. Greenwald, D.L. Hartill, W.H. Hopkins, D.L. Kreinick, B. Kreis, Z. Leong, Y. Li, X. Liu, J.A. Livezey, A. Lyndaker, J. Makita, M.P. McDonald, V. Medjidzade, R.E. Meller, T.I. O'Connell, S.B. Peck, D.P. Peterson, G. Ramirez, M.C. Rendina, P. Revesz, D.H. Rice, N.T. Rider, D. L. Rubin, D. Sagan, J.J. Savino, R.M. Schwartz, R.D. Seeley, J.W. Sexton, J.P. Shanks, J.P. Sikora, E.N. Smith, C.R. Strohman, H.A. Williams
  CLASSE, Ithaca, New York
• F. Antoniou, S. Calatroni, M. Gasior, O.R. Jones, Y. Papaphilippou, J. Pfingstner, G. Rumolo, H. Schmickler, M. Taborelli
  CERN, Geneva
• D. Asner
  Carleton University, College of Natural Sciences, Ottawa, Ontario
• L. Boon, A.F. Garfinkel
  Purdue University, West Lafayette, Indiana
• J.M. Byrd, C.M. Celata, J.N. Corlett, S. De Santis, M.A. Furman, A. Jackson, R. Kraft, D.V. Munson, G. Penn, D.W. Plate, M. Venturini
  LBNL, Berkeley, California
• B.T. Carlson
  Grove City College, Grove City, Pennsylvania
• T. Demma
  INFN/LNF, Frascati (Roma)
• R.T. Dowd
  ASCo, Clayton, Victoria
• J.W. Flanagan, P. Jain, K. Kanazawa, K. Kubo, K. Ohmi, H. Sakai, K. Shibata, Y. Suetsugu, M. Tobiyama
  KEK, Ibaraki
• D. Gonnella
  Clarkson University, Potsdam, New York
• W. Guo
  BNL, Upton, Long Island, New York
• K.C. Harkay
  ANL, Argonne
• R. Holtzapple
  CalPoly, San Luis Obispo, CA
• J.K. Jones, A. Wolski
  Cockcroft Institute, Warrington, Cheshire
• D. Kharakh, J.S.T. Ng, M.T.F. Pivi, L. Wang
  SLAC, Menlo Park, California
• M.C. Ross, C.-Y. Tan, R.M. Zwaska
  Fermilab, Batavia
• L. Schächter
  Technion, Haifa
• E.L. Wilkinson
  Loyola University, Chicago, Illinois

The Cornell Electron Storage Ring (CESR) has been reconfigured as a test accelerator (CesrTA) for a program of electron cloud (EC) research at ultra low emittance. The instrumentation in the ring has been upgraded with local diagnostics for measurement of cloud density and with improved beam diagnostics for the characterization of both the low emittance performance and the beam dynamics of high intensity bunch trains interacting with the cloud. Finally a range of EC mitigation methods have been deployed and tested. Measurements of cloud density and its impact on the beam under a range of conditions will be presented and compared with simulations. The effectiveness of a range of mitigation techniques will also be discussed.

Slides

• R. Tomás, B. Dalena, J. Pfingstner, D. Schulte, J. Snuverink
  CERN, Geneva
• J.K. Jones
  Cockcroft Institute, Warrington, Cheshire
• A. Latina
  Fermilab, Batavia
• J. Resta-López
  JAI, Oxford

The CLIC BDS tuning, alignment and feedbacks studies have been typically performed independently and only over particular sections of the BDS. An effort is being put to integrate all these procedures to realistically evaluate the luminosity performance.

• R.T.P. D'Arcy
  UCL, London
• D.J. Holder, B.D. Muratori
  Cockcroft Institute, Warrington, Cheshire
• J.K. Jones
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

EMMA (Electron Machine with Many Applications) is a prototype non-scaling Fixed Field Alternating Gradient (NS-FFAG) accelerator presently under construction at Daresbury Laboratory, UK. The energy recovery linac ALICE will serve as an injector for EMMA within the energy range of 10 to 20 MeV. The injection line consists of a symmetric 30° dogleg to extract the beam from ALICE, a matching section and a tomography section for transverse emittance measurements. This is followed by a transport section to the injection point of the EMMA ring. Commissioning of the EMMA injection line started in early 2010. A number of different injection energy and bunch charge regimes are planned; for some of the regimes the effects of space charge will be significant. It is therefore necessary to model the electron beam transport in this line using a code capable of both calculating the effect of, and compensating for, space charge. Therefore the General Particle Tracer (GPT) code has been used. A range of injection beam parameters have been modelled for comparison with experimental results.

• 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.

• J.K. Jones, D. Angal-Kalinin
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

It is proposed to investigate the option of moving the positron source to the end of the main linac as a part of the central integration in the International Linear Collider project. The positron source incorporates an undulator at the end of the main linac and the photons generated in the undulator are transported to the target, located at a distance of around 400m. The dogleg design has been optimised to provide the required transverse off-set at the location of the target and to give minimum emittance growth at 500 GeV. The design of the dogleg and the tolerances on beam tuning as a result of locating this dogleg in the beginning of the beam delivery system are presented.

• B.D. Muratori, J.K. Jones, A. Kalinin, A.J. Moss, Y.M. Saveliev, R.J. Smith, S.L. Smith, S.I. Tzenov, A.E. Wheelhouse
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• G. Cox
  STFC/DL, Daresbury, Warrington, Cheshire
• D.J. Holder
  Cockcroft Institute, Warrington, Cheshire
• D.J. Kelliher, S. Machida
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon

The first results from commissioning EMMA - the Electron Model of Many Applications- are summarised in this paper. EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). EMMA will be the world's first non-scaling FFAG and the paper will outline the characteristics of the beam injected in to the accelerator as well as summarising the results of the extensive EMMA systems commissioning. The paper will report on the results of simulations of this commissioning and on the progress made with beam commissioning.

• S.I. Tzenov, J.K. Jones, B.D. Muratori
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• Y. Giboudot
  Brunel University, Middlesex

Described in the paper are systematic procedures to inject and keep the beam on the reference trajectory for a fixed energy, as applied to the EMMA non scaling FFAG accelerator. The notion of accelerated orbits in FFAG accelerators has been introduced and some of their properties have been studies in detail.

• T.R. Edgecock
  STFC/RAL, Chilton, Didcot, Oxon
• C.D. Beard, J.A. Clarke, S.A. Griffiths, C. Hill, S.P. Jamison, J.K. Jones, A. Kalinin, K.B. Marinov, N. Marks, P.A. McIntosh, B.D. Muratori, J.F. Orrett, Y.M. Saveliev, B.J.A. Shepherd, R.J. Smith, S.L. Smith, S.I. Tzenov, A.E. Wheelhouse
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
• J.S. Berg
  BNL, Upton, Long Island, New York
• N. Bliss, B.G. Martlew, C.J. White
  STFC/DL, Daresbury, Warrington, Cheshire
• M.K. Craddock
  UBC & TRIUMF, Vancouver, British Columbia
• J.L. Crisp, C. Johnstone
  Fermilab, Batavia
• Y. Giboudot
  Brunel University, Middlesex
• E. Keil
  CERN, Geneva
• D.J. Kelliher, S. Machida
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon
• S.R. Koscielniak
  TRIUMF, Vancouver
• F. Méot
  CEA, Gif-sur-Yvette
• J. Pasternak
  Imperial College of Science and Technology, Department of Physics, London
• S.L. Sheehy, T. Yokoi
  JAI, Oxford

The Electron Model for Many Applications (EMMA) will be the World's first non-scaling FFAG and is under construction at the STFC Daresbury Laboratory in the UK. Construction is due for completion in March 2010 and will be followed by commissioning with beam and a detailed experimental programme to study the functioning of this type of accelerator. This paper will give an overview of the motivation for the project and describe the EMMA design and hardware. The first results from commissioning will be presented in a separate paper.