Nanodiamond diffraction gratings for neutron optics

Neutron optics and the neutron scattering and spectroscopy methods into which it has blossomed are key techniques for fundamental physics as well as for studies of condensed matter and material properties. I n view of the number of existing neutron-research centers and the effort put into facilities in Europe alone (for instance, the construction of the European Spallation Source ESS in Lund, Sweden), further development of neutron-optical techniques in addition to well-established methods is necessary. There is clear lack of versatile, compact and also low-cost alternatives to nowadays mostly bulky and expensive neutron optical components. To spark development of the latter, we intend to introduce grating-structures made of composites containing polymers and nanodiamonds (particles made from diamond, some nanometers of diameter), exhibiting optimized neutron-optical properties as efficient optical elements for slow neutrons. In particular, we create nanopatterns with dimensions of only a ten thousandth part of a millimeter by overlapping coherent laser beams (holography). These patterns serve as gratings by which neutrons (that can be regarded as waves, too) are diffracted---redirected by interference. The redirection can be controlled by the special properties and adjustment of the gratings, similarly to what is done in glasses, telescopes and microscopes using lenses, mirrors and other components known from light optics. The well-known physical principles behind state-of-the-art neutron-optics instrumentation can be revisited considering materials and methods developed for the prospering field of nanotechnology. Proof - of-principle experiments will demonstrate the applicability of such grating structures as add -ons to existing neutron-scattering instruments or for novel neutron-optical techniques.

Neutron optics and the neutron scattering and spectroscopy methods into which it has blossomed are key techniques for fundamental physics as well as for studies of condensed matter and material properties. In view of the number of existing neutron-research centers and the effort put into facilities in Europe alone (for instance, the construction of the European Spallation Source ESS in Lund, Sweden), further development of neutron-optical techniques in addition to well-established methods is necessary. There is clear lack of versatile, compact and also low-cost alternatives to nowadays mostly bulky and expensive neutron optical components. To spark development of the latter, we introduced grating-structures made of composites containing polymers and nanodiamonds (particles made from diamond, some nanometers of diameter), exhibiting optimized neutron-optical properties as efficient optical elements for slow neutrons. In particular, we created relativel large (several cm) nanopatterns with structure dimensions of only a ten thousandth part of a millimeter by overlapping coherent laser beams (holography). These patterns serve as gratings by which neutrons (that can be regarded as waves, too) are diffracted---redirected by interference. The redirection can be controlled by the special properties and adjustment of the gratings, similarly to what is done with glasses, telescopes and microscopes using lenses, mirrors and other components known from light optics. Proof-of-principle experiments demonstrated the applicability of such grating structures to build a new long-wavelength neutron interferometer, the tests of which are under way.