Optical klystron enhancement to self amplified spontaneous emission at FERMI

Giuseppe Penco, Enrico Allaria, Giovanni De Ninno, Eugenio Ferrari, Luca Giannessi, Eléonore Roussel, Simone Spampinati

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The optical klystron enhancement to a self-amplified spontaneous emission free electron laser has been studied in theory and in simulations and has been experimentally demonstrated on a single-pass high-gain free electron laser, the FERMI FEL-1, in 2014. The main concept consists of two undulators separated by a dispersive section that converts the energy modulation induced in the first undulator in density modulation, enhancing the coherent harmonic generation in the first part of the second undulator. This scheme could be replicated in a multi-stage: the bunching is enhanced after each dispersive section, consistently reducing the saturation length. We have applied the multi-stage optical klystron (OK) scheme on the FEL-2 line at FERMI, whose layout includes three dispersive sections. Optimizing the strength of the dispersions allowed a significant increase of the self-amplified spontaneous emission (SASE) intensity in comparison to a single-stage OK and extending to the soft-X rays the OK enhanced SASE previously demonstrated on FEL-1.
Original languageEnglish
Article number15
Pages (from-to)-
Issue number1
Publication statusPublished - 1 Mar 2017
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics
  • Instrumentation
  • Radiology Nuclear Medicine and imaging

Cite this

Penco, G., Allaria, E., De Ninno, G., Ferrari, E., Giannessi, L., Roussel, E., & Spampinati, S. (2017). Optical klystron enhancement to self amplified spontaneous emission at FERMI. Photonics, 4(1), -. [15]. https://doi.org/10.3390/photonics4010015