Author: Loos, H.
Paper Title Page
MOOA02 Beam Instrumentation for X-ray FELs 1
 
  • H. Loos
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by U.S. Department of Energy, Office of Basic Energy Sciences, under Contract DE-AC03-76SF00515.
The performance of X-ray Free-electron lasers depends strongly on the achieved quality of the high brightness electron beam and its shot by shot stability. The requirements and challenges of the instrumentation needed to tune and optimize such electron beams will be discussed. Of particular interest are measurements of the beam orbit, emittance, energy, and bunch length and the different measurement techniques for these transverse and longitudinal beam parameters and their implementation for routine operation will be addressed in detail, particularly the necessary instrumentation to fulfill different user requirements in terms of beam energy and bunch length. Specific requirements for the initial commissioning, routine optimization and feedback applications will be presented as well.
 
slides icon Slides MOOA02 [2.114 MB]  
 
TUPD38 Design of a Single-Shot Prism Spectrometer in the Near- and Mid-Infrared Wavelength Range for Ultra-Short Bunch Length Diagnostics 386
 
  • C. Behrens
    DESY, Hamburg, Germany
  • A.S. Fisher, J.C. Frisch, A. Gilevich, H. Loos, J. Loos
    SLAC, Menlo Park, California, USA
 
  The successful operation of high-gain free-electron lasers (FEL) relies on the understanding, manipulation, and control of the parameters of the driving electron bunch. Present and future FEL facilities have the tendency to push the parameters for even shorter bunches with lengths below 10 fs and charges well below 100 pC. This is also the order of magnitude at laser-driven plasma-based electron accelerators. Devices to diagnose such ultra-short bunches even need longitudinal resolutions smaller than the bunch lengths, i.e. in the range of a few femtoseconds. This resolution is currently out of reach with time-domain diagnostics like RF-based deflectors, and approaches in the frequency-domain have to be considered to overcome this limitation. Our approach is to extract the information on the longitudinal bunch profile by means of infrared spectroscopy using a prism as dispersive element. In this paper, we present the design considerations on a broadband single-shot spectrometer in the near- and mid-infrared wavelength range (0.8 - 39.0 μm).