Calculated brilliance spectra of the installed APPLE-II type undulator with circular and linear polarizations at a beam current of 500 mA. 1st, 3rd, and 5th in the legend indicate degrees of harmonics. 1% coupling machine operation is assumed in the calculation.
Layout (a) and photograph (b) of the SAMRAI beamline consisting of the APPLE-II type undulator (U7), the modified Wadsworth type monochromator (M0-S), and the high-resolution photoemission analyzer at the focal point. The monochromator mainly has five optical components: two plane mirrors (M0 and M1) with water cooling, one set of three spherical gratings (g), an exit slit (s), and one toroidal refocusing mirror (M3). The spherical gratings with a radius of 10 m are located 22 m from the center of the undulator. There is no entrance slit. S is located 6.47 m from G. A second branch for a VUV microscope end station is planned to be constructed after the plane mirror (M2) located between G and S.
Nine mirrors of M1 with water cooling.
Calculated and experimentally obtained -polarized reflectivity spectra with an incident angle of 7.5° of Mg/SiC multilayer mirrors installed at M1. These mirrors are optimized at photon energies of 31, 34, 37, and 40 eV.
Transmission spectra of helium absorption and argon window-type resonance measured with the G1 and G2 gratings, respectively, and an exit slit size of . The energy resolving powers were evaluated as 19 000 at 24.56 eV for G1 and 9000 at 29.19 eV for G2.
Theoretical energy resolving power with 1% (dashed lines) and 3% (solid lines) coupling constants of storage ring operation. The experimentally obtained energy resolving powers at 24.5 and 29.2 eV with G1 (solid circles) and G2 (open squares) with a 3% coupling constant are also plotted.
Obtained photon flux spectra (solid and dashed lines) with a exit slit ( of is roughly expected) of the combination of gratings, M1 mirrors, and undulator gap size. The marked lines are the trace of the peak intensity of the solid and dashed lines.
Schematic figure (a) and photograph (b) of the ARPES end station at the SAMRAI beamline (BL7U). The end station is equipped with a photoelectron analyzer (A-1 analyzer), a six-axis manipulator with a liquid-helium-flow type cryostat (i-GONIO virtual-shaft type) and a low-energy electron diffraction device to check sample rotation. Three pumps [turbo molecular pump (TMP), titanium sublimation pump (TSP), and ion pump (IP)] are used for making an ultrahigh vacuum.
(a) Angular distribution of photoelectrons of the angular-distribution test device at a kinetic energy of 2.47–2.794 eV excited by an undulator radiation of 10 eV. The angular space is 1°. The total acceptance angle of the analyzer is ±18°. (b) Magnified angular distribution of (a) near the center of the pixels. 1° consists of 5 pixels (0.2°/pixel). (c) Photo of the angular-distribution test device installed at the bottom of the sample manipulator.
An energy distribution curve (solid circles) of the Fermi cutoff of an evaporated Au film measured at the SAMRAI beamline using the excitation photon energy of 10 eV. The dashed line is a simulated Fermi edge obtained as a Gaussian function of 2 meV FWHM convoluted with the Fermi–Dirac distribution function (solid line) at 15 K. The total energy resolution was evaluated as less than 2 meV. Some of the parameters for the measurement are indicated in the figure.
3D FS image of CeSb measured at the SAMRAI beamline.
Characteristics of optical components of the Wadsworth monochromator in the SAMRAI beamline. The size of mirrors indicates . and of mirror 3 (M3) indicate the radii of longitudinal and sagittal focuses, respectively.
Design parameters for Mg/SiC wide-band multilayers in the 30–40 eV photon energy region.
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