Performance of a high-energy-resolution, tender x-ray synchrotron radiation beamline (invited)

Beamline X-24A at the National Synchrotron Light Source was designed for optimal performance in the x-ray spectral region 500–5000 eV. This choice of energy range placed a number of constraints on the beamline design, requiring a crystal monochromator in a windowless UHV environment. Although this increased the complexity of the design, there were compelling scientific reasons for our desire to work in this range. In addition to tunability over the selected energy range, a primary goal was to obtain the highest possible energy resolution in the primary beam. We have achieved incident energy resolution significantly better than the typical core-level lifetime broadening for this energy range. This has permitted studies of processes that are not broadened by lifetimes, such as resonant scattering and back-reflection x-ray standing-wave effects. In addition to high resolution, it was designed to collect and focus as much flux as possible from the bending magnet source.