The recent development of phase-grating moir\'e neutron interferometry promises a wide range of impactful experiments from dark-field imaging of material microstructure to precise measurements of fundamental constants. However, the contrast of 3 % obtained using this moir\'e interferometer was well below the theoretical prediction of 30 % using ideal gratings. It is suspected that non-ideal aspects of the phase-gratings was a leading contributor to this deficiency and that phase-gratings needed to be quantitatively assessed and optimized. Here we characterize neutron diffraction from phase-gratings using Bragg diffraction crystals to determine the optimal phase-grating orientations. We show well-defined diffraction peaks and explore perturbations to the diffraction peaks and the effects on interferometer contrast as a function of grating alignment. This technique promises to improve the contrast of the grating interferometers by providing in-situ aides to grating alignment.
@article{arxiv.1812.07097,
title = {Optimization of neutron diffraction from phase-gratings},
author = {B. Heacock and D. Sarenac and D. G. Cory and M. G. Huber and D. S. Hussey and C. Kapahi and H. Miao and H. Wen and D. A. Pushin},
journal= {arXiv preprint arXiv:1812.07097},
year = {2020}
}