Present Status of a New Vacuum Ultraviolet and Soft X-Ray Undulator Beamline BL-13A for the Study of Organic Thin Films Adsorbed on Surfaces

The present status of a new vacuum ultraviolet/soft X-ray (VUV/SX) beamline (BL-13A) used for the study of organic thin films adsorbed on surfaces is described. The base pressure of BL-13A is maintained below 1×10−8 Pa in order to prevent contamination of the optics by residual gases. The measured performance is as follows: photon-energy region, 30-1,200 eV; photon flux, 109-1011 photons s−1; photon-energy resolution (E/ΔE), 10,000 at a photon energy of 401 eV; spot size (horizontal\ imes;vertical) at the second focus, ≈630×120 μm; photon-energy drift, ≤±0.02 eV at a photon energy of 244.39 eV; reduction of photon flux in the C K-edge region, ∼50%.