Selection of the geometry of the Moessbauer experiment on scattering taking into account cosine spectra distortion

It is reported that cosine distortion for the Moessbauer spectrum brings about line expansion, decrease in its amplitude and the shift of its position to higher velocities. These changes are the more pronounced the further is the line from velocity zero in the spectrum and the higher is its body angle value. The application of a source with the minimum possible spot diameter with the retention of its activity is suggested, and the collimation conditions are discussed