CLÆSS: The hard X-ray absorption beamline of the ALBA CELLS synchrotron

CLÆSS is a general-purpose absorption spectroscopy beamline at the ALBA CELLS Spanish synchrotron. Its optical layout is presented here along with its powerful capabilities for collecting absorption spectra with high signal to noise ratio in an unusually wide energy range (2.4–63.2 keV). Continuous energy scanning for quick scans is available, allowing to collect X-ray absorption near edge structure and extended X-ray absorption fine structure spectra in 3–5 and 8–10 min, respectively. The full automatization of the beamline allows performing successive measurements at different conditions without attending to the beamline. The different experimental setups available to users are reported. Examples of XAS measurements are presented, showing the performances of the beamline at different standard conditions.