A soft X‐ray (80–1500 eV) grazing‐incidence monochromator with varied‐line‐spacing plane gratings at PF‐BL‐11A

The design and performance of a new soft X‐ray beamline BL‐11A at the Photon Factory (PF) are presented. A Hettrick‐type grazing‐incidence monochromator equipped with three varied‐line‐spacing plane gratings was designed and constructed at a bending‐magnet source of the PF 2.5 GeV storage ring. An 800 lines mm −1 laminar grating produced by aspheric‐wavefront holographic recording optics, as well as a mechanically ruled blazed one, were tested. A resolving power of more than 4500 was achieved at 400 eV with either grating, and ∼10 10  photons s −1 are available at a resolving power of 2000. High photon flux enables low‐concentration samples, such as surface adsorbates, to be studied. A simple scanning mechanism for a wide energy range is quite useful for EXAFS measurements on light elements such as C, N and O.