A Multilayer-Coated Diffraction-Grating Device for Polarized and Unpolarized Neutron Interferometry

This work is devoted to a new generation of cold-neutron interferometers based on bidimensional diffraction. The use of multilayer coatings in the classical Ioffe difffraction-grating neutron interferometer is proposed. This interferometer combines the properties of two periodic structures, namely the dispersion by a diffraction grating and the high reflectivity ensured by the multilayer coating. All the cold-neutron interferometer devices (two diffraction gratings and two mirrors) must be multilayered with Ni–Ti or Fe–Ge for unpolarized or polarized neutron interferometry experiments, respectively. The computed results, giving the characteristics of the multilayer-coated amplitude diffraction grating are discussed within a kinematic model. An Ni–Ti multilayered amplitude diffraction grating for use at λ = 5 Å is presented as an example.