Mössbauer spectroscopy with synchrotron radiation

Synchrotron radiation is an attractive source for Mössbauer spectroscopy because of its unique properties, such as, short pulse nature, large brightness, well-defined polarization and high collimation. Due to the delta-pulse excitation of the nuclear resonance, the intensity of the subsequent decay is measured energy integrated as a function of time, instead of time integrated as a function of energy (source/absorber velocity), like in a conventional Mössbauer experiment. The resulting time spectrum contains the full information of the Mössbauer parameters and is essentially source independent. Thus, in contrast to the conventional technique, source related complications in the data analysis are completely removed. In addition, the well-defined polarization of the SR-pulse facilitates the analysis in general and the study of polarization phenomena in particular. Two examples, namely the measurements of the temperature dependence and polarization mixing of forward scattering from α-57Fe nuclei are presented.