The Naval Research Laboratory’s new hard x‐ray beamline at the National Synchrotron Light Source

The Naval Research Laboratory is currently rebuilding its hard x‐ray beamline at the National Synchrotron Light Source (NSLS, X‐23B) to increase the flux and energy range. The optical and mechanical design of the new configuration is described and its performance predicted. The new design contains a fixed‐exit pair of mirrors for harmonic rejection and source collimation and a fixed‐exit two‐crystal monochromator with sagittally focusing second crystal. In addition, the horizontal acceptance of the line will be increased from 6 to 18 mrad. The line is expected to focus radiation to a spot 0.5 mm vertical by 1.0 mm horizontal in the energy range 2 to 30 keV. At 8.5 keV a throughput of 5.7×1012 photons/s/200 mA is expected with an E/ΔE of 5×103 with Si (111) crystals, a factor of 10 to 30 over present beamline throughput. The increased flux is due to improved mirror surfaces, decreased optical aberrations from conical sagittal focusing, and the increased horizontal acceptance.