Ultrafast time-resolved small-angle X-ray scattering setup on the FemtoMAX beamline

The design and main characteristics of the ultrafast time-resolved small-angle X-ray scattering (TR-SAXS) setup on the FemtoMAX beamline at MAX IV are described. TR-SAXS experiments have successfully been performed in a transmission geometry investigating solid gold nanospheres sealed in a quartz capillary. The femtosecond laser pump and X-ray probe technique has been used to commission the setup and follow the dynamics in the laser-excited solid nanoparticles. This commissioning experiment on the FemtoMAX beamline has revealed picosecond thermal expansion dynamics in gold nanostructures. The results demonstrate the beamline's potential for probing ultrafast phenomena in condensed matter systems employing the SAXS technique. This method complements the available diffraction techniques on the FemtoMAX beamline and opens new capabilities for investigating light-induced structural dynamics in solid-state materials.