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

Abstract

Recent Mössbauer experiments in a rotating system conducted by Friedman et al. (EPL (2016) 114, 50010; J. Synchr. Rad. (2017) 24, 661; J. Synchr. Rad. (2019) 26, 473) involve the application of synchrotron radiation onto a spinning semi-circular resonant absorber. The physical interpretation of these authors’ methodology, and its alleged performance improvement, is analyzed in the light of our own team’s past experience based instead on the traditional laboratory setup (e.g., Kholmetskii, A.L., et al. Ann. Phys. (2016) 374, 247; Eur. Phys. J. Plus (2018) 133, 261). It is shown that a number of fundamental shortcomings in the Friedman et al. approach deprives it of any practical significance with respect to the improvement of the technique of Mössbauer rotor experiments with a synchrotron source (Friedman, Y., et al. J. Synchr. Rad. (2019) 26, 473). We conclude 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 an emitted and absorbed resonant radiation in a rotating system.