A VUV BEAMLINE (ABL-3B) FOR REAL-TIME PHOTOELECTRON-SPECTROSCOPY AT THE NTT SYNCHROTRON-RADIATION FACILITY

A VUV beamline (ABL-3B) for real-time photoelectron spectroscopy has b een developed at the normal-conducting accelerating ring (NAR) of the NTT synchrotron radiation facility. To accept the incident synchrotron radiation beam with the wide horizontal divergence angle of 20 mrad, a 1.38-m-long cylindrically bent front mirror was devised. This mirror was composed of four plane mirror blocks connected together and mount ed on a steel holder beam having a C-shaped cross section. The mirror holder can be bent by a novel bending device with a momentum of 1388 k g cm to achieve the optimum radius of the curvature of 63.9 m. The foc used spot of 3.5 mm (H) x 1.8 mm (V) was preliminarily obtained on the sample position by bending the front mirror. When the stored electron beam current was 50 mA and the ''grasshopper'' monochromator was tune d at 130 eV, a photon flux of 1.5 x 10(10) photons/s was obtained with the energy resolution of 0.5 eV.