Author: Muratori, B.D.
Paper Title Page
WEP136 Modelling of the EMMA ns-FFAG Ring Using GPT 1734
 
  • R.T.P. D'Arcy
    UCL, London, United Kingdom
  • J.K. Jones, B.D. Muratori
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  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 Aug 2010. The energy recovery linac ALICE will serve as an injector for EMMA, within an energy range of 10-20 MeV. The injection line consists of a dogleg to extract the beam from ALICE, a matching section, and 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 forty two cells, each containing one focusing and one defocusing quadrupole. Commissioning of the EMMA ring started in late 2010. A number of different injection energy and bunch charge regimes are planned; for some of the regimes the effects of space charge may be significant. It is therefore necessary to model the electron beam transport in the injection line and 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 modelled for comparison with experimental results.  
 
WEP234 Longitudinal Dynamics in the EMMA ns-FFAG 1927
 
  • J.M. Garland, H.L. Owen
    UMAN, Manchester, United Kingdom
  • N. Bliss
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • J.A. Clarke, N. Marks, B.D. Muratori
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  Funding: Work supported by the Science and Technology Facilities Council UK. Grant Number: ST/G004277/1
EMMA is the first non-scaling FFAG to be constructed, whose use of linear magnets means that the accelerating electron bunch rapidly crosses many resonances. We have modeled the capture and acceleration of bunches in the serpentine channel created by the radio-frequency cavities, and compare it to a proposed experiment in which induction cells allow slow acceleration. Two induction cores each providing ~20kV over 1.65 μs enable a number of resonance crossing experiments.