DESIGN OF A HIGH-FLUX AND HIGH-RESOLUTION VUV BENDING-MAGNET BEAMLINE

A high-flux and high-resolution VUV beamline (4-40 eV) has been design ed and is under construction at SRRC. This beamline, which collects 50 mrad of horizontal radiation, uses a 6 m cylindrical-grating monochro mator with an incident angle of 70 degrees instead of the conventional normal-incidence-monochromator (NIM) design. Special features, such a s movable entrance slit, bendable vertical focusing mirror and movable curved exit slit, are employed to enhance greatly the beamline perfor mance. With both slit openings set at 10 mu m, the energy-resolving po wer can reach as high as 70000. Photon fluxes of 1 x 10(13) and 1 x 10 (10) photons s(-1) are calculated for energy-resolving powers of 1000 and 40000, respectively. The best image size at the sample position is smaller than 0.45 x 0.2 mm.