Performance of the 18 m-spherical grating monochromator newly developed in the UVSOR facility

An 18 m spherical grating monochromator with high resolution and high photon flux has been constructed at the bending magnet beamline BL2B2 of the UVSOR facility in the Institute for Molecular Science. The monochromator covers the energy range of 20–200 eV with three gratings. The resolving power (E/ΔE) has been estimated by ion yield spectra of rare gas atoms (He, Ar and Kr) to be 2000–8000 under the conditions of a photon flux of 1×1010 photons s−1 and a ring current of 100 mA. A second-order light of 7% is contained at a photon energy of 45.6 eV.