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 designed and is under construction at SRRC. This beamline, which collects 50 mrad of horizontal radiation, uses a 6 m cylindrical-grating monochromator with an incident angle of 70° instead of the conventional normal-incidence-monochromator (NIM) design. Special features, such as movable entrance slit, bendable vertical focusing mirror and movable curved exit slit, are employed to enhance greatly the beamline performance. With both slit openings set at 10 µm, the energy-resolving power can reach as high as 70000. Photon fluxes of 1 × 10¹³ and 1 × 10¹⁰ 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 × 0.2 mm.