Parametric gamma-radiation in Fe crystal with natural splitting of the Mössbauer line

It is shown that the spectral density of the parametric gamma-radiation (PGR) is sensitive to the splitting of the Mössbauer lines. PGR spectrum in the Fe crystal is calculated in the framework of the kinematical diffraction theory. The brightness of the PGR source proves to be comparable with the resonant γ-quanta source based on the synchrotron radiation.