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.
