The FXE instrument will enable ultrafast pump–probe experiments on ultrafast timescales—below 100 femtoseconds—for a broad scientific user community.

The instrument comprises two independent secondary X-ray emission spectrometers next to a 1-Mpx detector for scattering studies. Its main research is devoted to dynamic studies of chemical and biochemical reactions in liquids next to different solid-state applications. With a powerful laser as pump source, it will permit studies with femtosecond time resolution exploiting different observables via a suite of hard X-ray tools (which may be further expanded over time):

• X-ray diffraction (XRD)
• X-ray diffuse scattering (XDS), or wide-angle X-ray scattering (WAXS)
• X-ray emission spectroscopies (XES): non-resonant, or resonant inelastic X-ray scattering (RIXS)
• X-ray absorption spectroscopies: X-ray absorption near-edge structure (XANES), or extended X-ray absorption fine structure (EXAFS)

The FXE scientific instrument will serve a broad scientific community and will embrace several fields of ultrafast X-ray science and their applications. State-of-the-art femtosecond instrumentation and techniques, both for X-rays and optical lasers, will deliver new information about geometric and electronic structures serving applications in many fields, and particular in the areas of

• Chemical dynamics
• Photovoltaic applications
• Photosynthesis
• Catalytic processes
• Material physics

Operation of the FXE instrument is planned to start in 2017. A more detailed description of the science case of FXE can be found in the FXE TDR and CDR.

The main specifications and beam parameters of FXE are summarized in table 1 below. Further technical details about the available equipment at FXE is available here and in the TDR and CDR or by contacting the FXE group.