The first undulator beamline at the Pohang Light Source for high-resolution spectroscopy and spectromicroscopy

The first insertion device at the Pohang Light Source, U7, was fabricated a nd installed in 1997. The beamline of the undulator U7 was designed for hig h-resolution spectroscopy and spectromicroscopy in the photon energy range from 20 to 2000 eV. A variable-included-angle plane-grating monochromator h ad been chosen as a monochromator for the beamline. The estimated spectral resolution, E/Delta E, of the beamline is above 7000 in the photon energy r ange below 600 eV, and above 4000 for the remaining photon energy range. Th e estimated flux at the sample is on the order of 10(12) [photons/s/0.1% BW ]. The estimated spot size, at a photon energy of 45 eV, is 190x310 mu m at the high-resolution spectroscopy branch; and 55x140 mu m at the spectromic roscopy branch. A scanning photoemission microscope (SPEM) and a scanning t ransmission X-ray microscope (STXM), with an estimated spot size of 0.1 mu m, is under installation at the spectromicroscopy branch. A multi-purpose, high-resolution surface analysis system is under development at the spectro scopy branch by the Atomic-scale Surface Science Research Center of Yonsei University, in South Korea. This surface analysis system offers angle-resol ved ultraviolet photoelectron spectroscopy, high-resolution X-ray photoelec tron spectroscopy, spin-resolved photoelectron spectroscopy, and X-ray phot oelectron diffraction. (C) 1999 Elsevier Science B.V. All rights reserved.