DNP Seminar

10-22-2025 11:00 Conference hall (bldg. 42, 3rd floor)

"Neutron passage through the accelerating crystal"

 Alexander Frank¹⁾,

Vladimir Bushuev²⁾, Maxim Zakharov¹⁾, German Kulin¹⁾

¹⁾FLNP JINR ²⁾ Moscow State University

 

Abstract

This paper is initiated by the results of [1], in which a change in neutron energy was registered during the passage through an accelerating crystal under conditions close to the Bragg conditions. It was shown that, just as in the case of long-wavelength neutrons passing through a refractive sample [2,3], the accelerated motion of the sample results in a change in neutron energy. The physical nature of the phenomenon in both cases is estimated by the difference in the Doppler frequency shift at the entrance and exit of the sample. The difference between the case of conventional refraction of long-wavelength neutrons and the case of wave passage through a crystal under conditions where diffraction has the dominant impact on the nature of wave propagation is only quantitative.

This interpretation of the phenomenon differs from the viewpoint of the authors of [1] that believe the neutron's kinetic energy is constant while it is within the accelerating crystal but changes upon exiting it. In this report, we intend to present the results of a numerical experiment (quantum "movie") demonstrating the erroneousness of this viewpoint and to show that the results of the experiment can be explained within the framework of well-known concepts of neutron diffraction in a crystal and the time delay of a wave as it passes through the sample.

 

• P. Braginetz, Y.A. Berdnikov, V.V. Fedorov et al. Phys. Atom. Nuclei80, 38–45 (2017).
• I. Frank, P. Geltenbort, M. Jentschel, D. V. Kustov, G. V. Kulin, V. G. Nosov, and A. N. Strepetov. Phys. At. Nucl. 71, 1656–1674 (2008).
• I. Frank, P. Geltenbort, M. Jentschel, D. V. Kustov,G. V. Kulin, and A. N. Strepetov. JETP Lett. 93, 361–365 (2011).