We investigate nano- and subnanometer-structure of materials by diffraction, spectroscopy, and imaging with synchrotron x-ray radiation. Our attention is mainly focused on the development of x-ray instrumentation and technique and the exploitation of its application fields. The following are current studies.

(1) Development of time-resolved small-angle x-ray scattering (SAXS)
      and its application to soft materials:

We develop time-resolved SAXS, which enables us to measure the dynamics of the nano-structure of soft materials (polymer, biomaterials, lipids, and liquid crystals) in a time-resolution of milli- and micro-second order. Simultaneous measurement of nano- and subnanometer-structure is also performed by the combination with wide-angle x-ray scattering (WAXS). High brilliance of synchrotron x-ray radiation makes it possible to perform x-ray micro-beam experiments. By using an x-ray micro-beam, we measure the spatial inhomogeneity of nano- and subnanometer-structures on a micron-scale and aim to reveal the relationship between the structure and the properties of materials.

(2) Development of x-ray universal ellipsometer and x-ray polarization microscope:

Interaction between x-ray polarization and anisotropy of materials now attracts large attention, although the degree of interaction is very small and few studies on the subject have been performed both experimentally and theoretically. We have developed an x-ray universal ellipsometer and now perform the high-accurate measurements of optical anisotropy (linear birefringence and linear dichroism) and optical activity (circular birefringence and circular dichroism). By using the x-ray universal ellipsometer, element-specific measurement is possible, which enables us to study subtle changes in structure which are accompanied with phase transitions and chemical reactions. We also have developed an x-ray polarization microscope and have successfully visualized the anisotropic bulk structure owing to the high penetration power of x-rays.

(3) Development and evaluation of high performance x-ray detector and x-ray optics:

We have developed the high-performance detector to make the best use of synchrotron x-ray radiation. For example, the development of arrayed-CCD x-ray detectors for protein crystallography and the evaluation of imaging plates have been performed.