Author: Jackson, F.
Paper Title Page
WG2003
Investigation of Beam Dynamics with Not-ideal Electron Beam on ALICE ERL  
 
  • Y.M. Saveliev, F. Jackson, J.K. Jones, J.W. McKenzie
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A. Wolski
    The University of Liverpool, Liverpool, United Kingdom
 
  ALICE, an energy recovery linac based accelerator, drives an IR-FEL and is a source of broadband coherently enhanced THz radiation. It also serves as a test-bed for various accelerator physics experiments. The beam dynamics, both transverse and longitudinal, is therefore of primary importance. The overview of the machine lattice and the design beam dynamics are described. As with many other machines in this class, the electron beam in ALICE is not always of perfect quality. This is aggravated by the fact that, currently, the quantum efficiency map of the photocathode is not fully uniform and the operating voltage of the HV DC photoelectron gun is only 230kV compared to design value of 350kV. Results of the experimental investigation of the beam dynamics and data analysis at these conditions are presented. The emphasis is made on understanding the physics that may affect the overall beam quality and on interpretation and analysis of experimental data.  
slides icon Slides WG2003 [2.330 MB]  
 
WG2023
Longitudinal Dynamics in the ALICE Injection Line  
 
  • J.W. McKenzie, F. Jackson, Y.M. Saveliev
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  The ALICE Energy Recovery Linac at Daresbury Laboratory drives an IR-FEL and serves as a source of coherent THz radiation. For these uses, the demands on transverse emittance are quite relaxed, however, the longitudinal dynamics need to be carefully controlled. The IR-FEL demands bunch length less than 1 ps and energy spread around 100 keV. The amount of THz produced is also strongly dependent on the bunch length. The ALICE injector consists of a DC photocathode gun, currently operating at 230 keV, followed by a single-cell buncher cavity and a superconducting booster module which accelerates the beam up to 6.5 MeV. An injection line transports this relatively low energy beam for around 13 m, including a number of bends, prior to injection into the main linac. We observe appreciable development in the longitudinal phase space of the beam in this injection line. The longitudinal dynamics of the beam in the first acceleration stage and along the long injection line will be discussed with reference to simulations and measurements.  
slides icon Slides WG2023 [2.285 MB]