First results from a 6 m/10 m toroidal grating monochromator for soft x-rays

A toroidal grating monochromator (TGM) has been tested at the VUV ring of the NSLS at Brookhaven National Laboratory. The instrument combines three 6 m (entrance-to-exit-slit distance) and three 10 m gratings with 10 and 4° angles of incidence, respectively. The optics is designed for high resolution from 5 to 700 eV photon energy, e.g. 7, 25, 80 and 130 meV at 25, 70, 300 and 500 eV according to ray tracings for a grating illumination of 3 rad × 15 mrad (1.5 mrad × 3.75 mrad) for the 6 m (10 m) gratings. The usable photon energy range (limited by stray light) was found to extend up to 1300 eV. Photon fluxes of about 1011 photons/s in a 1 eV window have been observed for the 10 m TGM. A resolution of better than 0.17 eV has been observed at the C(1s) level. © 1984.