• S. Reiche, R. Abela, H.-H. Braun, B. Patterson, M. Pedrozzi
  PSI, Villigen

The X-ray FEL facility SwissFEL, currently planned at the Paul Scherrer Institut, is primarily based on the SASE operation of a hard (1-7 Å) and soft (7-70 Å) X-ray beamline. However the soft X-ray FEL beamline is foreseen to allow for seeding down to 1 nm. The intrinsic shot noise in the electron bunch demands excellent state-of-the-art seeding sources and strategies. This presentation discusses various seeding options for the PSI-XFEL and evaluates them regarding performance and risk of implementation.

• S. Reiche, R. Abela, B. Beutner, H.-H. Braun, B. Patterson, M. Pedrozzi
  PSI, Villigen

The Paul Scherrer Institute is currently proposing a X-ray Free-electron Laser facility operating in the wavelength range of 0.1 to 7 nm. The overall design aims for a compact layout and relies on a low emittance electron beam and short period undulator. As an initial step, a 250 MeV is currently under construction to demonstrate a high brightness electron beam sufficient for operating the SwissFEL. An extension of the 250 MeV injector is under construction to test additional key components for the SwissFEL. Those are prototypes of the in-vacuum undulator modules as well as the proof-of-principle demonstration of echo-enabled harmonic generation as a possible seeding option for the SwissFEL at 1 nm. The combination of seeding and prototype undulator module allows for saturation of the FEL at 50 nm and first experiments with FEL radiation at the PSI.

• A. Oppelt, R. Abela, B. Beutner, B. Patterson, S. Reiche
  PSI, Villigen

A powerful THz source is being considered for THz-pump / X-ray probe experiments at the planned SwissFEL. The source should deliver half-cycle pulses of less than 1 ps duration with an energy of 100 μJ in a focal region of 1 mm². Design considerations and simulations for such a source fulfilling the challenging parameter combination will be presented.