Seeding at SwissFEL

Abstract

SwissFEL at the Paul Scherrer Institute is a free-electron laser facility providing hard and soft x-rays, based on the SASE principle. In addition, the soft x-ray beamline Athos is currently extended for electron beam manipulation with external lasers, aiming to provide seeding capabilities based on the two-stage echo-enabled harmonic generation (EEHG) scheme. Completion of the installation is foreseen in spring 2023. We present the initial results on the single-stage operation for ESASE and mode-locked lasing and give an outlook on the expected performance for seeding down to 1 nm.