Outline and present status of Beamline BL01B1 at SPring-8 are presented. Several typical spectra observed at BL01B1 are shown. XAFS in high energy region and XAFS utilizing the modulation technique, which elucidates the structure at relaxed excited state or intermediate state of chemical reaction, are explored.
Present status of the Structure Analysis Beamline (BL02B1) is described. This beamline is constructed for structure analysis of a single crystal and powder sample under extreme conditions by four subgroups. The performance on X-ray diffraction is in progress during this half year, and many advanced experiments are now possible to be carried out. Several experimental results are given as examples.
Performances of the high pressure in-situ X-ray observation system using a large volume multi anvil press installed at the High-Pressure Mineral Physics Experimental Station at BL04B1 in SPring-8 are introduced. Recent results obtained with this system are reviewed.
The facilities of the beam line BL04B1 (High-Temperature Station) at SPring-8 are presented and the experimental apparatus installed is described in details. Energy-dispersive x-ray diffraction measurements at BL04B1 for expanded fluid Hg and Se were carried out in the wide density range from the liquid near the melting point to the supercritical region including the metal-nonmetal transition region. The measurements for liquid Te at high temperatures were also made. The structure factor S (k) and the pair distribution function g (r) were obtained. Based on these results structural changes with decreasing density are discussed from the microscopic point of view.
We report on the initial test of undulator tuning for the beamline BL10XU at Spring-8. The optics of BL10XU is quite simple, i.e., major optical components are a rotated-inclined double crystal monochromator designed by Ishikawa and a double flat mirror. One of a standard in-vacuum type undulator (U032V) is used. Since a typical energy range of - 1 keV is required as a routine EXAFS scan, both monochromator and undulator gap should be controlled during a scan; an undulator gap is varied so that a monochromator acceptance can track the undulator peak. On varying an undulator gap from 9.6 mm to 22 mm, a wide energy range (5-30 keV) is covered. We demonstrate that undulator tuning can provide glitch-free transmission spectra with a high energy resolution (1.5 eV at 9 keV) .
Recent advance in high-pressure technique has enabled us to reach a pressure of a few hundreds gigapascals with a diamond anvil cell. At such extremely high pressures, materials are highly compressed and exhibit various novel characters which can not be realized under ambient condition. A diffractometer installed at the second station of BL10XU was designed and constructed for polycrystalline x-ray diffraction measurement at ultrahigh pressures. Recent research activities at this station are described and a future perspective of ultrahigh-pressure synchrotron radiation science is briefly discussed.
Current status of the high pressure research on BL14B1 JAERI beamline at the SPring-8 is presented. A cubic type multi-anvil high pressure device is currently used for an in situ X-ray diffraction studies of materials under high pressure and high temperature conditions. By switching the optics, either white or monochromatic X-rays is available for powder X-ray diffraction experiments with energy dispersive or angle dispersive methods as well as XAFS measurements.
JAERI Group has constructed three beamlines for carrying out their own research at SPring-8. One of the three is the bending magnet Beamline for the purpose of materials research. We will describe here the feature of the beam line and the spectrometer, and also some data which have been recently taken at this beamline.
Studies of magnetic materials by spectroscopy and diffractometry are developed further using high brilliant light sources at SPring-8. Polarization tunability of incident photons and polarization analysis of scattered X-rays are a promising item for studying electronic and magnetic structures in various magnetic materials. Feasibility of the diffractometer, installed on BL39XU for X-ray magnetic scattering and absorption experiments, is shown by recent results of X-ray magnetic circular dichroism, X-ray magnetic diffraction, and X-ray resonant magnetic scattering. For the experiments, phase retarder using a diamond single crystal plays an essential role for regulation of the polarization states and for recording the magnetic effects with high accuracy.
The Bio-Crystallography beamline (BL41XU) dedicated for X-ray crystallography of biological macromolecules is a public beamline opened from October, 1997. The X-ray source is an in-vacuum type standard undulator at SPring-8, and a rotated inclined double-crystal monochromator includes a pin-post water cooling silicon crystal on which a tremendous heat load from the undulator deposits. The focal spot in an experimental station has a size of 200 micron and 300 micron in horizontal and vertical directions, respectively. The flux is 5×1012 photons/sec for 12.4 keV X-rays at a storage ring current of 100 mA. In order to align optical elements and a diffractometer after every changes of X-ray energy and sample-detector distance, an automated procedure has been developed within the energy range from 6.5 keV to 37.5 keV. The diffractometer specially designed for macromoleculer crystallography at BL41XU is working with a CCD detector and imaging plate detectors. BL41XU has been constructed for two scientific targets: (1) routine structure analyses of biological macromolecules on the MIR-OAS technique and (2) X-ray crystallography on biologically significant supra-complexes and macromolecules crystallized only into a small size less than 50 micron. Almost of beamline commissioning required for the first target have been completed and many crystal structures have already been reported. For the second target of beamline construction, the commissioning will be continued to open the frontier of structural biology.
RIKEN structural biology beamline I (BL45XU) is an undulator beamline with two branches. One is for protein crystallography (PX) and the other is for small-angle x-ray scattering (SAXS) . PX and SAXS experiments can be done simultaneously [Yamamoto et al. (1995) Rev. Sci. Instrum. 66, 1833-1835] . For SAXS branch the clean and stable optics were realized. The use of this Beamline extends the various limits of small-angle scattering technique: measurements of dilute protein solutions, large protein complex and fast time-resolved experiments. These advantages will be fully utilized for high-pressure SAXS measurements.
RIKEN beamline II (BL44B2) is dedicated to macromolecular crystallography in white and monochromatic X-ray mode, and XAFS of diluted biological systems. The user run was started since April 1998, and lots of scientific applications including time-resolved (intermediate state) protein crystallography, protein crystallography at atomic resolution, phasing with anomalous scattering, membrane protein crystallography, and fluorescence XAFS of diluted metalloproteins have been emerging.