X-ray free-electron lasers (FELs) are state-of-the-art scientific tools capable to study matter
on the scale of atomic processes. Since the initial operation of X-ray FELs more than a …

We present the generation of x-ray pulses with average pulse energies up to one millijoule
and rms pulse durations down to the femtosecond level. We have produced these intense …

Directly observing atomic motions in molecules during chemical dynamics has long
constituted one of the grand challenges in chemistry. 1 The emergence of X-ray free …

Th 229 with a low-lying nuclear isomeric state is an essential candidate for a nuclear clock
as well as many other applications. Laser excitation of the isomeric state has been a long …

Femtosecond pump-probe spectroscopy using ultrafast optical and infrared pulses has
become an essential tool to discover and understand complex electronic and structural …

The intrinsic energy spread of electron beams needs to be measured to characterize and
optimize high-brightness electron beam sources such as those driving x-ray free-electron …

Abstract At the Paul Scherrer Institute, two electron accelerator-based photon sources are in
operation, namely a synchrotron source, the swiss light source (SLS), and an X-ray free …

X-ray free-electron lasers (FELs) are modern research tools with applications in multiple
scientific fields. Standard x-ray FEL pulses are produced by the self-amplified spontaneous …

Nonlinear wave mixing in the X-ray range can provide valuable insights into the structural
and electron dynamics of atomic and molecular systems on ultrafast time scales, with state …

Ultrafast single-particle imaging with intense x-ray pulses from free-electron laser sources
provides a new approach for visualizing structure and dynamics on the nanoscale. After a …