Author: Williams, J.E.
Paper Title Page
WEPSM17 Non-Invasive Beam Detection in a High-Average Power Electron Accelerator 1082
 
  • J.E. Williams, S. Biedron, J.R. Harris, S.V. Milton
    CSU, Fort Collins, Colorado, USA
  • S.V. Benson, P.E. Evtushenko, G. Neil, S. Zhang
    JLAB, Newport News, Virginia, USA
 
  For a free-electron laser (FEL) to work effectively the electron beam quality must meet exceptional standards. In the case of an FEL operating at infrared wavelengths in an amplifier configuration the critical phase space tends to be in the longitudinal direction. Achieving high enough longitudinal phase space density directly from the electron injector system of such an FEL is difficult due to space charge effects, thus one needs to manipulate the longitudinal phase space once the beam energy reaches a sufficiently high value. However, this is fraught with problems. Longitudinal space charge and coherent synchrotron radiation can both disrupt the overall phase space, furthermore, the phase space disruption is exacerbated by the longitudinal phase space manipulation process required to achieve high peak current. To achieve and maintain good FEL performance one needs to investigate the longitudinal emittance and be able to measure it during operation preferably in a non-invasive manner. Using the electro-optical sampling (EOS) method, we plan to measure the bunch longitudinal profile of a high-energy (~120-MeV), high-power (~10kW or more FEL output power) beam.