Comparison of traditional and synchrotron beam methodologies in Mössbauer experiments in a rotating system.

Recent Mössbauer experiments in a rotating system reported by others in the literature have involved the application of synchrotron radiation onto a spinning semi-circular resonant absorber. Here, the physical interpretation of these methodologies, and their alleged performance improvement, is analyzed in the light of our own team's past experience based instead on the traditional laboratory setup. It is shown that a number of fundamental shortcomings in the approach reported in the literature deprives it of any practical significance with respect to the improvement of the technique of Mössbauer rotor experiments with a synchrotron source. It is concluded that, at present, only Mössbauer experiments relying on an ordinary compact source of resonant radiation and a resonant absorber both fixed on the rotor promise to provide crucial information with respect to the physical origin of the observed energy shift between emitted and absorbed resonant radiation in a rotating system.

Elaborations on Mössbauer rotor experiments with synchrotron radiation and with usual resonant sources.

A comparative analysis of Mössbauer experiments in a rotating system between a recent application using synchrotron radiation [Friedman et al. (2016). Eur. Phys. Lett. 114, 50010; Friedman et al. (2017). J. Synchrotron Rad. 24, 661-666] and usual sources of resonant radiation is carried out. The principal methodological difference between these experiments can be related to the fact that in the former set of experiments the source of the resonant radiation rests in a laboratory frame whereas for the latter set of experiments the source is attached to a rotating system. It is concluded that the utilization of ordinary Mössbauer sources remains the most promising path for further research appertaining to the Mössbauer effect in rotating systems.