Abstract
Ultrahigh monochromatic 14.4 keV X-rays with a narrow bandwidth of 15.4 neV were generated successfully with a high counting rate of 12,000 counts/s at the undulator beamline (BL11XU) of SPring-8. It was achieved by combining an intense X-ray from the third generation synchrotron radiation facility SPring-8 and pure nuclear Bragg scattering of a very high-quality 57FeBO3 perfect single crystal at the Néel temperature. We describe the detailed study of the beam characteristics and some performance test experiments of energy-domain synchrotron radiation Mössbauer spectroscopy, including a high-pressure experiment using a diamond anvil cel.