Author: Evain, C.
Paper Title Page
A New Scheme for Recording Electron Bunch Shapes with High Resolution and Record Recording Length: Principle and Tests at European XFEL  
  • S. Bielawski
    PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France
  • C. Evain, E. Roussel, C. Szwaj
    PhLAM/CERLA, Villeneuve d’Ascq, France
  • C. Gerth, B. Steffen
    DESY, Hamburg, Germany
  Funding: CEMPI Labex, CPER photonics for society, METEOR CNRS/MOMENTUM grant.
Non-destructive, single-shot recording of longitudinal bunch profiles is a prerequisite for accelerator commissioning and operation. A common strategy for the measurement of ultra-short electron bunches is to sample the Coulomb field with femtosecond laser pulses. In recent years, such electro-optic detection schemes evolved to compact and reliable techniques. However, serious limitations on time resolution have been encountered, when long recording lengths are required. This has been recognised as a fundamental bottleneck and coined the term "Fourier limit". We present here a novel electro-optic sampling strategy that is theoretically capable to overcome this limit and achieve femtosecond resolution for any recording length. This new approach is based on the mathematical concept of information diversity. We present first results obtained both with table-top experiments as well as at the European XFEL. This technique opens the way to ultrafast electric field shape characterization with femtosecond resolution in new situations, including longitudinal bunch profile monitoring, studies of microbunching instabilities, and THz pulses generated at free-electron lasers.
video icon
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)