Passage of neutrons through accelerating crystal and the acceleration effect

The problem of changing the energy of a neutron when it passes through an accelerating crystal under conditions close to the Bragg condition is considered. It is shown that, similar to the case of the passage of long-wavelength neutrons through a refractive sample, the accelerated motion of a crystal results in a change in neutron energy. The physical nature of the phenomenon in both cases is determined by the difference in the Doppler frequency shift at the entrance and exit of the wave through the sample. The difference between the case of ordinary refraction of long-wavelength neutrons and the case of wave passage through a crystal under conditions where diffraction has a dominant influence on the nature of wave propagation is only quantitative. The results obtained are qualitatively consistent with the available experimental data.