High-resolution and low-temperature photoemission spectroscopy at the HiSOR helical-undulator beamline

We report an experimental system dedicated for high-resolution and low-temperature photoemission spectroscopy installed on the helical-undulator beamline of a compact 700 MeV electron-storage ring (HiSOR) at Hiroshima University. A 3 m off-plane Eagle normal-incidence monochromator at the beamline covers the photon-energy range of hnu = 4-40 eV. From the photoemission spectra near the Fermi edge of evaporated Au film, the total energy resolution was estimated to be 4.5 and 7.5 meV at hnu = 7.1 and 22.6 eV, respectively. We have also performed photoemission measurements of Yb metal which demonstrated highly bulk-sensitive spectra for the excitation by low energy photon. The high-resolution photoemission spectra of Y1-xCaxTiO3 with x = 0.41 in the vicinity of the boundary between the metallic and insulating phases exhibited anomalous temperature dependence in comparison with those of normal metals.