Pulse duration of seeded free-electron lasers

Paola Finetti, Hauke Höppner, Enrico Allaria, Carlo Callegari, Flavio Capotondi, Paolo Cinquegrana, Marcello Coreno, Riccardo Cucini, Miltcho B. Danailov, Alexander Demidovich, Giovanni De Ninno, Michele Di Fraia, Raimund Feifel, Eugenio Ferrari, Lars Fröhlich, David Gauthier, Torsten Golz, Cesare Grazioli, Yun Kai, Gabor KurdiNicola Mahne, Michele Manfredda, Nikita Medvedev, Ivaylo P. Nikolov, Emanuele Pedersoli, Giuseppe Penco, Oksana Plekan, Mark J. Prandolini, Kevin C. Prince, Lorenzo Raimondi, Primoz Rebernik, Robert Riedel, Eleonore Roussel, Paolo Sigalotti, Richard Squibb, Nikola Stojanovic, Stefano Stranges, Cristian Svetina, Takanori Tanikawa, Ulrich Teubner, Victor Tkachenko, Sven Toleikis, Marco Zangrando, Beata Ziaja, Franz Tavella, Luca Giannessi

Research output: Contribution to journalReview article

29 Citations (Scopus)


The pulse duration, and, more generally, the temporal intensity profile of free-electron laser (FEL) pulses, is of utmost importance for exploring the new perspectives offered by FELs; it is a nontrivial experimental parameter that needs to be characterized. We measured the pulse shape of an extreme ultraviolet externally seeded FEL operating in high-gain harmonic generation mode. Two different methods based on the cross-correlation of the FEL pulses with an external optical laser were used. The two methods, one capable of single-shot performance, may both be implemented as online diagnostics in FEL facilities. The measurements were carried out at the seeded FEL facility FERMI. The FEL temporal pulse characteristics were measured and studied in a range of FEL wavelengths and machine settings, and they were compared to the predictions of a theoretical model. The measurements allowed a direct observation of the pulse lengthening and splitting at saturation, in agreement with the proposed theory.
Original languageEnglish
Article number021043
Pages (from-to)-
JournalPhysical Review X
Issue number2
Publication statusPublished - 16 Jun 2017
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Finetti, P., Höppner, H., Allaria, E., Callegari, C., Capotondi, F., Cinquegrana, P., Coreno, M., Cucini, R., Danailov, M. B., Demidovich, A., Ninno, G. D., Fraia, M. D., Feifel, R., Ferrari, E., Fröhlich, L., Gauthier, D., Golz, T., Grazioli, C., Kai, Y., ... Giannessi, L. (2017). Pulse duration of seeded free-electron lasers. Physical Review X, 7(2), -. [021043]. https://doi.org/10.1103/PhysRevX.7.021043