Techniques for inelastic X-ray spectroscopy with μeV-resolution

Abstract We introduce a novel type of spectrometer that provides a μeV bandpass together with a tunability over a few meV. The technique relies on nuclear resonant scattering (Mossbauer effect) of synchrotron radiation at the 14.4-keV resonance of 57 Fe. Energy tuning is achieved by the Doppler effect in high-speed rotary motion. The resonantly scattered monochromatic radiation is extracted by a polarization filtering technique or by spatial separation due to the “nuclear lighthouse effect”.