Author: Jones, J.K.
Paper Title Page
MOPPP038 Optics Design and Layout for the Electron Beam Test Facility at Daresbury Laboratory 646
 
  • D. Angal-Kalinin, J.W. McKenzie, B.L. Militsyn
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • J.K. Jones
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  An Electron Beam Test Facility (EBTF) is being developed at Daresbury Laboratory to provide the beam for industrial applications and as a front end of future light source facility test under consideration. The RF photoinjector will deliver ~6 MeV beam to industrial users* and will serve as an injector for the future light source facility under consideration at Daresbury**. The Photoinjector design in first phase consists of 2.5 cell RF gun (on loan from Strathclyde) to be driven by Ti:S laser. The photo injector design is aimed to deliver bunches with 10-250 pC bunch charge at low transverse emittances and short bunch lengths. The beam transport optics design described in this paper includes a dedicated diagnostics section capable of measuring ultra short and ultra low emittance bunches and transport to two user areas.
* P. McIntosh, these proceedings.
** J. Clarke, these proceedings.
 
 
TUPPP068 Comparison of Compression Schemes for CLARA 1756
 
  • P.H. Williams, J.W. McKenzie
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • J.K. Jones, P.H. Williams
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  CLARA (Compact Linear Advanced Research Accelerator) at Daresbury Laboratory is proposed to be the UK’s national FEL test facility. The accelerator will be a ~250 MeV electron linac capable of producing short, high brightness electron bunches. The machine comprises a 2.5 cell RF photocathode gun, one 2 m and three 5 m normal conducting S-band (2998MHz) accelerating structures and a variable magnetic compression chicane. CLARA will be used as a test bed for novel FEL configurations. We present a comparison of acceleration and compression schemes for the candidate machine layout.  
 
MOPPC079 Modelling of the EMMA ns-FFAG Ring Using GPT 319
 
  • R.T.P. D'Arcy, S. Jolly
    UCL, London, United Kingdom
  • J.K. Jones, B.D. Muratori
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • S.B. van der Geer
    Pulsar Physics, Eindhoven, The Netherlands
 
  EMMA (Electron Machine with Many Applications) is a prototype non-scaling Fixed-Field Alternating Gradient (ns-FFAG) accelerator whose construction at Daresbury Laboratory, UK, was completed in the autumn of 2010. The energy recovery linac ALICE will serve as an injector for EMMA, within an energy range of 10 to 20 MeV. The injection line consists of a symmetric 30 degree 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. The ring is composed of 42 cells, each containing one focusing and one defocusing quadrupole. Acceleration over many turns of the EMMA machine has recently been confirmed. In some cases the bunch will traverse upwards of 100 turns, at which point the effects of space-charge may be significant. It is therefore necessary to model the electron beam transport in the ring 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 modeled for comparison with experimental results.  
 
MOPPP023 Effect of DC Photoinjector Gun Voltage on Beam Dynamics in ALICE ERL 616
 
  • Y.M. Saveliev, F. Jackson, J.K. Jones, J.W. McKenzie
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  The ALICE ERL employs a DC HV photoelectron gun as an electron source. As with other machines in this class, the electron beam is not always of perfect quality. This is aggravated by that the ALICE gun has been operated so far at lower 230kV voltage compared to the design value of 350kV due to hardware limitations. The “two beams” structure was observed and experimentally investigated and found to be the result of complex processes during initial stages of beam acceleration. The experimental observations and data will be compared with those obtained at a nominal 350kV gun voltage. An investigation of the effect of the DC photogun voltage on longitudinal and transverse beam dynamics will be presented and discussed.  
 
MOPPR061 Computing Bunch Charge, Position, and BPM Resolution in Turn-by-Turn EMMA BPMs 924
 
  • A. Kalinin, J.K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R.G. Borrell
    WareWorks Ltd, Manchester, United Kingdom
  • G. Cox
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • D.J. Kelliher, S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • I.W. Kirkman
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  The NS-FFAG electron model ‘EMMA’ and its Injection and Extraction Lines are equipped with a total of 53 EPICS VME BPMs*. In the BPMs, each opposite button signal pair is time-domain-multiplexed into one channel as a pulse doublet. The recording of turn-by-turn data into the BPM memory is triggered by the bunch itself on each of its passages. For each accelerating cycle, the BPMs deliver a snapshot of a turn-by-turn trajectory measured in each of 42 cells. Additional BPMs (two pairs) are used to obtain a Poincare map. We describe the EPICS architecture, and a set of Python data processing algorithms that are used to automatically set a BPM intensity range, to eliminate an error due to tails of the doublet pulses, to calculate the bunch charge and position, and, for a set of injections, to find the BPM resolution. We use three types of button pickup mappings** that allow: to eliminate bunch charge signal dependence on offset, to get a linear offset response, and to eliminate ‘quadrupole’ signal dependence on offset as well (which is used in resolution calculation). We present beam measurement results collected in 2011 runs.
* A. Kalinin et al., Proc. of IPAC’10, MOPE068, p. 1134, (2010.
** I. Kirkman, these proceedings.
 
 
TUPPD020 An EMMA Racetrack 1452
 
  • B.D. Muratori, J.K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • H.L. Owen
    UMAN, Manchester, United Kingdom
 
  EMMA (Electron Machine for Many Applications) is the world’s first prototype non-scaling electron FFAG hosted at Daresbury Laboratory. Several upgrade possibilities for EMMA are explored, from creating a dispersion-free region in the ring to facilitate injection and extraction to making an insertion in EMMA by turning it into a racetrack-style machine. Alternative methods of injection and extraction into the EMMA ring are explored together with their feasibility and implications. The option of developing nested racetracks to achieve a particular desired energy is also explored.  
 
TUPPD021 Orbit Correction in the EMMA Non-scaling FFAG – Simulation and Experimental Results 1455
 
  • D.J. Kelliher, S. Machida, S.L. Sheehy
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • J.S. Berg
    BNL, Upton, Long Island, New York, USA
  • J.K. Jones, B.D. Muratori
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • E. Keil
    Honorary CERN Staff Member, Berlin, Germany
  • I.W. Kirkman
    The University of Liverpool, Liverpool, United Kingdom
 
  The non-scaling FFAG EMMA (Electron Model for Many Applications) is currently in operation at Daresbury Laboratory, UK. Since the lattice is made up solely of linear elements, the betatron tune varies strongly over the momentum range according to the natural chromaticity. Orbit correction is complicated by the resulting variation in response to corrector magnet settings. We consider a method to optimise correction over a range of fixed momenta and discuss experimental results. Measurements of the closed orbit and response matrix are included.  
 
TUPPD068 Design of the Production and Measurement of Ultra-Short Electron Bunches from an S-band RF Photoinjector 1560
 
  • J.W. McKenzie, D. Angal-Kalinin, J.K. Jones, B.L. Militsyn
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  The Electron Beam Test Facility (EBTF) is planned for installation in late 2012 at Daresbury Laboratory. An S-band RF photoinjector provides ultrashort, low emittance electron bunches up to 6 MeV. A suite of diagnostics has been designed to fully characterise the bunches. A particular focus has been on producing and measuring bunch lengths less than 100 fs. This can be achieved with a multi-cell standing wave S-band transverse deflecting cavity. Operating such a cavity with low energy electrons provides certain challenges which are discussed in this paper with respect to beam dynamic simulations.  
 
TUPPP066 CLARA - A Proposed New FEL Test Facility for the UK 1750
 
  • J.A. Clarke, D. Angal-Kalinin, D.J. Dunning, S.P. Jamison, J.K. Jones, J.W. McKenzie, B.L. Militsyn, N. Thompson, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • R. Bartolini
    JAI, Oxford, United Kingdom
  • I.P.S. Martin
    Diamond, Oxfordshire, United Kingdom
 
  A new single pass national FEL test facility, CLARA, is proposed to be constructed at Daresbury Laboratory in the UK. The aim of CLARA is to develop a normal conducting test accelerator able to generate longitudinally and transversely bright electron bunches and to use these bunches in the experimental production of stable, synchronized, ultra short photon pulses of coherent light from a single pass FEL with techniques directly applicable to the future generation of light source facilities. In addition the facility will be an ideal test bed for demonstrating innovative technologies such as high repetition rate normal conducting RF linacs and advanced undulator designs. This paper will describe the design of CLARA, pointing out the flexible features that will be incorporated to allow multiple novel FEL schemes to be proven.  
 
TUPPP069 A Compact, Modular Electron Beam Delay Line for Use in Novel Free-Electron Laser Schemes 1759
 
  • J.K. Jones, J.A. Clarke, N. Thompson
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Two Free-Electron Laser (FEL) schemes have been proposed, for the generation of attosecond pulse trains* and for the improvement of the longitudinal coherence of SASE FELs**, in which repeated electron delays are implemented within the undulator lattice. To obtain the maximum performance and flexibility from these schemes it is advantageous to use an electron delay line that satisfies the isochronicity conditions, as well as being compact, modular and, ideally, variable. In this paper we present initial designs for such a system, along with simulations of its performance. We investigate both in-undulator and out-of-undulator designs, and compare the applicability of each for various aspects of the FEL design, as well as commenting on the mechanical and magnetic implications of the schemes.
* N.R. Thompson and B.W.J. McNeil. Phys. Rev. Lett. 100, 203901 (2008).
** N.R. Thompson, D.J. Dunning and B.W.J. McNeil, IPAC2010, TUPE050, p. 2257 (2010).
 
 
WEOAB01 New Results from the EMMA Experiment 2134
 
  • B.D. Muratori, J.K. Jones
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • C.S. Edmonds, K.M. Hock, M.G. Ibison, I.W. Kirkman
    The University of Liverpool, Liverpool, United Kingdom
  • J.M. Garland, H.L. Owen
    UMAN, Manchester, United Kingdom
  • D.J. Kelliher, S. Machida
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. After demonstration of acceleration in the serpentine channel in April 2011, the beam study with EMMA continues to explore the large transverse and longitudinal acceptance and effects of integer tune crossing with slower rate on the betatron amplitude. Together with a comparison of detailed models based on measured field maps and the experimental mapping of the machine by relating the initial and final phase space coordinates. These recent results together with more practical improvements such as injection orbit matching with real-time monitoring of the coordinates in the transverse phase space will be reported in this paper.  
slides icon Slides WEOAB01 [2.120 MB]  
 
THPPR044 A New Electron Beam Test Facility (EBTF) at Daresbury Laboratory for Industrial Accelerator System Development 4074
 
  • P.A. McIntosh, D. Angal-Kalinin, S.R. Buckley, J.A. Clarke, A.R. Goulden, C. Hill, S.P. Jamison, J.K. Jones, A. Kalinin, J.W. McKenzie, K.J. Middleman, B.L. Militsyn, T.T. Ng, B.J.A. Shepherd, R.J. Smith, S.L. Smith, N. Thompson, A.E. Wheelhouse
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • N. Bliss, G.P. Diakun, A. Gleeson, T.J. Jones, B.G. Martlew, A.J. Moss, L. Nicholson, M.D. Roper, C.J. White
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
 
  Recent UK government funding has facilitated the implementation of a unique accelerator test facility which can provide enabling infrastructures targeted for the development and testing of novel and compact accelerator technologies, specifically through partnership with industry and aimed at addressing applications for medicine, health, security, energy and industrial processing. The infrastructure provision on the Daresbury Science and Innovation Campus (DSIC) will permit research into areas of accelerator technologies which have the potential to revolutionise the cost, compactness and efficiency of such systems. The main element of the infrastructure will be a high performance and flexible electron beam injector facility, feeding customised state-of-the-art testing enclosures and associated support infrastructure. The facility operating parameters and implementation status will be described, along with primary areas of commercialised technology development opportunities.