X-ray beamlines for structural studies at the NSRRC superconducting wavelength shifter

Using a superconducting-wavelength-shifter X-ray source with a photon flux density of 10¹¹–10¹³ photons s⁻¹ mrad⁻¹ (0.1% bandwidth)⁻¹ (200 mA)⁻¹ in the energy range 5–35 keV, three hard X-ray beamlines, BL01A, BL01B and BL01C, have been designed and constructed at the 1.5 GeV storage ring of the National Synchrotron Radiation Research Center (NSRRC). These have been designed for structure-related research using X-ray imaging, absorption, scattering and diffraction. The branch beamline BL01A, which has an unmonochromatized beam, is suitable for phase-contrast X-ray imaging with a spatial resolution of 1 µm and an imaging efficiency of one frame per 10 ms. The main beamline BL01B has 1:1 beam focusing and a medium energy resolution of ∼10⁻³. It has been designed for small-angle X-ray scattering and transmission X-ray microscopy, used, respectively, in anomalous scattering and nanophase-contrast imaging with 30 nm spatial resolution. Finally, the branch beamline BL01C, which features collimating and focusing mirrors and a double-crystal monochromator for a high energy resolution of ∼10⁻⁴, has been designed for X-ray absorption spectroscopy and high-resolution powder X-ray diffraction. These instruments, providing complementary tools for studying multiphase structures, have opened up a new research trend of integrated structural study at the NSRRC, especially in biology and materials. Examples illustrating the performances of the beamlines and the instruments installed are presented.