Current status of the soft x-ray undulator beamline BL-2C. Varied space plane grating monochromator

A new grazing incidence soft x-ray monochromator has been constructed on the undulator beamline BL-2C of the Photon Factory. The monochromator has been designed to meet the demands for high-resolution soft x-ray spectroscopy. The monochromator has employed a varied space plane grating and a configuration with sagittal focusing and converging beam by an extra-focusing mirror in order to achieve requirement. According to analytical estimation and ray tracing simulation, the high resolving power beyond 10000 can be obtained over the full energy range from 250 to 1400 eV. Preliminary experiments have been done on three points concerning the resolving power, photon flux, and spot size. The results have showed the typical resolving power from 7500 to 10000, the absolute photon flux of the order of 1010 photons/s/300 mA/0.02%BW, and the spot size of 0.1 (V) x 0.9 (H) mm2 FW at the sample position. (author)