The PAL-XFEL at Pohang Accelerator Laboratory in South Korea provides the best performance and stability for atomic—and femtosecond-level spatiotemporal resolution. Currently, one FEL line each at the hard X-ray and soft X-ray beamlines is in operation, and ten experimental techniques are available for XFEL sciences in physics, materials, chemistry, and biology.
After seven years of user...
Despite significant advancements in generating attosecond pulses in the extreme ultraviolet and soft X-ray regimes, achieving high-power attosecond pulses at Ångstrom wavelengths has remained a considerable challenge. The generation of intense attosecond hard X-ray pulses is pivotal for probing the structural and electronic dynamics of matter with unprecedented precision. Recently, we proposed...
The free-electron laser FLASH at DESY delivers femtosecond pulses of light from the vacuum ultraviolet to the soft X-ray domain at an average repetition rate of 5kHz. Pulses from the free electron laser can be split and delayed and combined with other sources such as optical lasers and an undulator THz source to perform ultrafast time-resolved experiments. The FLASH facility allows for a large...
Stimuli-responsive polymers are an important class of materials with many applications in nanotechnology and drug delivery. The most prominent one is poly-N-isopropylacrylamide (PNIPAm) which has a lower critical solution temperature (LCST) around 32 °C. Below the LCST the polymer is swollen with water, while at higher temperatures the water is expelled from the polymer. The characterization...
The SwissFEL currently provides the hard X-ray endstations Alvra, Bernina, and Cristallina. Especially Alvra is a forerunner in the crystallographic community, having successfully performed many serial femtosecond crystallography experiments, using both, high-viscosity extruders (HVE) and GDVN jets as the sample delivery method [1-3]. With the recently commissioned SwissMX experiment based at...
Thermal deformation and performance of the crystal optics for high-repetition-rate Free Electron Lasers (FEL) critically depends on the pulse energy and repetition frequency among many other parameters. Time-domain modeling of the thermal deformation of the crystal can help to define acceptable operational parameters across the pulse-energy repetition-rate phase space. In this paper, we...
An acute understanding of photocatalytic reaction dynamics on metal oxides is crucial for the efficient development of technology used for self-cleaning surfaces and for air and water purification. By utilizing femtosecond X-ray laser pulses synchronized with an optical laser (1.6 eV) at FLASH in Hamburg we were able to directly follow the reaction dynamics during photocatalysis at the surface...
