Impact of non-Gaussian electron energy heating upon the performance of a seeded free-electron laser.

E. Ferrari, E. Allaria, W. Fawley, L. Giannessi, Z. Huang, G. Penco, and S. Spampinati Elettra-Sincrotrone Trieste S.C.p.A. di interesse nazionale, Strada Statale 14-km 163,5 in AREA Science Park, 34149 Basovizza, Trieste, Italy Universita degli Studi di Trieste, Dipartimento di Fisica, Piazzale Europa 1, 34127 Trieste, Italy SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA Enea, via Enrico Fermi 45, 00044 Frascati, Roma, Italy Laboratory of Quantum Optics, University of Nova Gorica, 5000 Nova Gorica, Slovenia Department of Physics, University of Liverpool, Oxford Street L69 7ZE, Liverpool, United Kingdom Cockcroft Institute, Sci-Tech Daresbury, Keckwick Lane WA4 4AD, Daresbury, Warrington, United Kingdom (Received 11 October 2013; published 21 March 2014)