New test of the dynamic theory of neutron diffraction by a moving grating

Maxim Zakharov,Alexander Frank,German Kulin,Semyon Goryunov,A Verkheev,V Chudoba,A Friesen,I Bobrikov,A Aparin

doi:10.1051/epjconf/201817703005

Abstract

Recently, multiwave dynamical theory of neutron diffraction by a moving grating was developed. The theory predicts that at a certain height of the grating profile a significant suppression of the zero-order diffraction may occur. The experiment to confirm predictions of this theory was performed. The resulting diffracted UCNs spectra were measured using time-of-flight Fourier diffractometer. The experimental data were compared with the results of numerical simulation and were found in a good agreement with theoretical predictions.

Highlights

Diffraction of neutron waves, like most other neutron-optical phenomena, has been considered for a long time from the point of the demonstration of the wave properties of a neutron and for the test of the predictions of stationary quantum mechanics
It was shown [1,2,3] that in the case of an absorbing or a phase grating moving across a monochromatic beam of ultracold neutrons (UCN), the grating can serve as a quantum modulator of a transmitted wave and the spectrum of neutrons passed through it is discrete
The model includes a numerical calculation of the spectrum of UCN transmitted through a rotating radial grating using formalism of dynamic theory of neutron diffraction on moving grating [8], as well as a Monte Carlo simulation of the process of measuring of the neutron spectrum obtained after diffraction

Summary

Introduction

Diffraction of neutron waves, like most other neutron-optical phenomena, has been considered for a long time from the point of the demonstration of the wave properties of a neutron and for the test of the predictions of stationary quantum mechanics. Neutron diffraction under certain conditions can be considered as a nonstationary phenomenon It was shown [1,2,3] that in the case of an absorbing or a phase grating moving across a monochromatic beam of ultracold neutrons (UCN), the grating can serve as a quantum modulator of a transmitted wave and the spectrum of neutrons passed through it is discrete. The phenomenon of neutron diffraction on a moving grating has found its application in experiments on the test of the weak equivalence principle for a neutron [4]. The continuation of this investigation [5,6,7] and recent theoretical results [8] required a more rigorous investigation of the UCN spectra after diffraction by a moving grating

Theory of neutron diffraction from a moving grating

Experiment

Conclusion