Experimental station Bernina at SwissFEL: condensed matter physics on femtosecond time scales investigated by X-ray diffraction and spectroscopic methods.

The Bernina instrument at the SwissFEL Aramis hard X-ray free-electron laser is designed for studying ultrafast phenomena in condensed matter and material science. Ultrashort pulses from an optical laser system covering a large wavelength range can be used to generate specific non-equilibrium states, whose subsequent temporal evolution can be probed by selective X-ray scattering techniques in the range 2-12 keV. For that purpose, the X-ray beamline is equipped with optical elements which tailor the X-ray beam size and energy, as well as with pulse-to-pulse diagnostics that monitor the X-ray pulse intensity, position, as well as its spectral and temporal properties. The experiments can be performed using multiple interchangeable endstations differing in specialization, diffractometer and X-ray analyser configuration and load capacity for specialized sample environment. After testing the instrument in a series of pilot experiments in 2018, regular user operation begins in 2019.

Dynamics of the photoinduced insulator-to-metal transition in a nickelate film.

Material properties can be controlled via strain, pressure, chemical composition, or dimensionality. Nickelates are particularly susceptible due to their strong variations of the electronic and magnetic properties on such external stimuli. Here, we analyze the photoinduced dynamics in a single crystalline NdNiO3 film upon excitation across the electronic gap. Using time-resolved reflectivity and resonant x-ray diffraction, we show that the pump pulse induces an insulator-to-metal transition, accompanied by the melting of the charge order. Finally, we compare our results with similar studies in manganites and show that the same model can be used to describe the dynamics in nickelates, hinting towards a unified description of these photoinduced electronic ordering phase transitions.

Opportunities for Chemistry at the SwissFEL X-ray Free Electron Laser.

X-ray techniques have long been applied to chemical research, ranging from powder diffraction tools to analyse material structure to X-ray fluorescence measurements for sample composition. The development of high-brightness, accelerator-based X-ray sources has allowed chemists to use similar techniques but on more demanding samples and using more photon-hungry methods. X-ray Free Electron Lasers (XFELs) are the latest in the development of these large-scale user facilities, opening up new avenues of research and the possibility of more advanced applications for a range of research. The SwissFEL XFEL project at the Paul Scherrer Institute will begin user operation in the hard X-ray (2.1-12.4 keV) photon energy range in 2018 with soft X-ray (240-1930 eV) user operation to follow and here we will present the details of this project, it's operating capabilities, and some aspects of the experimental stations that will be particularly attractive for chemistry research. SwissFEL is a revolutionary new machine that will complement and extend the time-resolved chemistry efforts in the Swiss research community.

Perspective: Opportunities for ultrafast science at SwissFEL.

We present the main specifications of the newly constructed Swiss Free Electron Laser, SwissFEL, and explore its potential impact on ultrafast science. In light of recent achievements at current X-ray free electron lasers, we discuss the potential territory for new scientific breakthroughs offered by SwissFEL in Chemistry, Biology, and Materials Science, as well as nonlinear X-ray science.

Science opportunities at the SwissFEL X-ray Laser.

Next-generation X-ray sources, based on the X-ray Free Electron Laser (XFEL) concept, will provide highly coherent, ultrashort pulses of soft and hard X-rays with peak intensity many orders of magnitude higher than that of a synchrotron. These pulses will allow studies of femtosecond dynamics at nanometer resolution and with chemical selectivity. They will produce diffraction images of organic and inorganic nanostructures without deleterious effects of radiation damage.

Science Opportunities at the SwissFEL X-ray Laser.

Next-generation X-ray sources, based on the X-ray Free Electron Laser (XFEL) concept, will provide highly coherent, ultrashort pulses of soft and hard X-rays with peak intensity many orders of magnitude higher than that of a synchrotron. These pulses will allow studies of femtosecond dynamics at nanometer resolution and with chemical selectivity. They will produce diffraction images of organic and inorganic nanostructures without deleterious effects of radiation damage.

Ultrafast structural dynamics in condensed matter.

We review our recent activity in the field of photo-induced structural dynamics in crystalline solids studied using femtosecond X-ray diffraction techniques.