A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z    

McNeil, B.W.J.

Paper Title Page
RPPT019 Start to End Simulations of the ERL Prototype at Daresbury Laboratory 1643
 
  • C. Gerth, M.A. Bowler, B.D. Muratori, H.L. Owen, N. Thompson
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • B. Faatz
    DESY, Hamburg
  • B.W.J. McNeil
    Strathclyde University, Glasgow
  
  Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that will serve as a research and development facility for the study of beam dynamics and accelerator technology important to the design and construction of the proposed 4th Generation Light Source (4GLS) project. Two major objectives of the ERLP are the demonstration of energy recovery and of energy recovery from a beam disrupted by an FEL interaction as supplied by an infrared oscillator system. In this paper we present start-to-end simulations of the ERLP including such an FEL interaction. The beam dynamics in the high-brightness injector, which consists of a DC photocathode gun and a superconducting booster, have been modelled using the particle tracking code ASTRA. After the booster the particles have been tracked with the code GPT which includes space charge in the injector line at 8.3 MeV. The 3D code GENESIS 1.3 was used to model the FEL interaction with the electron beam at 35 MeV.  
RPPT021 Inducing Strong Density Modulation with Small Energy Dispersion in Particle Beams and the Harmonic Amplifier Free Electron Laser 1718
 
  • B.W.J. McNeil, G.R.M. Robb
    Strathclyde University, Glasgow
  • M.W. Poole
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  
  Funding: We acknowledge the support of the European Union's EUROFEL Design Study, CCLRC, and the Scottish Universities Physics Alliance.

We present a possible method of inducing a periodic density modulation in a particle beam with little increase in the energy dispersion of the particles. The flow of particles in phase space does not obey Liouville's Theorem. The method relies upon the Kuramoto-like model of collective synchronism found in free electron generators of radiation, such as Cyclotron Resonance Masers and the Free Electron Laser. For the case of an FEL interaction, electrons initially begin to bunch and emit radiation energy with a correlated energy dispersion which is periodic with the FEL ponderomotive potential. The relative phase between potential and particles is then changed by approximately 180 degrees. The particles continue to bunch, however, there is now a correlated re-absorption of energy from the field. We show that, by repeating this relative phase change many times, a significant density modulation of the particles may be achieved with only relatively small energy dispersion. A similar method of repeated relative electron/radiation phase changes is used to demonstrate supression of the fundamental growth in a high gain FEL so that the FEL lases at the harmonic only.