TY - CHAP AU - Geloni, Gianluca A3 - Jaeschke, Eberhard A3 - Khan, Shaukat A3 - Schneider, Jochen R. A3 - Hastings, Jerome B. TI - Self-Seeded Free-Electron Lasers CY - Cham PB - Springer International Publishing M1 - PUBDB-2016-00003 SP - 1-28 PY - 2015 N1 - (c) Springer International Publishing Switzerland AB - Self-seeding is an active filtering method for Free-Electron Lasers (FELs) enabling the production of nearly Fourier-limited pulses in the X-ray frequency range where external seeding is not available. Schematically, it is composed by three parts: a Self-Amplified Spontaneous Emission (SASE) FEL working in the linear regime, a monochromator, and an FEL amplifier. Active filtering is achieved by letting the FEL pulse produced in the SASE FEL through the monochromator, while the electron beam is sent through a bypass, and its microbunching is destroyed due to dispersion. The filtered SASE pulse, serving as a seed, is recombined with the electron beam at the entrance of the FEL amplifier part. It is then amplified up to saturation and possibly beyond via post-saturation tapering. This allows for the production of high-brightness, nearly single-mode FEL pulses. The technique has been or will be implemented in a number of X-ray FEL (XFEL) facilities under operation or in the construction phase. In this chapter, we review the principle of self-seeding, its practical realizations, and related techniques. LB - PUB:(DE-HGF)7 UR - <Go to ISI:>//WOS:00 DO - DOI:10.1007/978-3-319-04507-8_4-1 UR - https://bib-pubdb1.desy.de/record/292720 ER -