Nanodiamond diffraction gratings for neutron optics (Austrian Science Fund - FWF, proj. no. P35597)

Contributors

• Juergen Klepp (PI, University of Vienna)
• Martin Fally (University of Vienna)
• Elhoucine Hadden (University of Vienna, Institut Laue Langevin)
• Christian Pruner (University of Salzburg)
• Yasuo Tomita (University of Electrocommunications)

Goal

Develop and improve neutron optical components based on nanodiamond

Abstract

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 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 from which neutrons are diffracted. The redirection can be controlled by the special properties and adjustment of the gratings, similarly to what is done in eyeglasses, 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.

Published articles:

• "Multilayer volume holographic gratings from Bayfol HX: light and neutron optical characteristics", Saba Shams Lahijani, Tobias Jenke, Christian Pruner, Juergen Klepp, Martin Fally, Proc. SPIE 12574, Holography: Advances and Modern Trends VIII, 1257403 (2023), doi: 10.1117/12.2665169 (ArXiv version: https://arxiv.org/abs/2304.03059 )
  
  
• "Holographic nanodiamond–polymer composite grating with unprecedented slow-neutron refractive index modulation amplitude", Elhoucine Hadden, Martin Fally, Yuko Iso, Tobias Jenke, Juergen Klepp, Atsushi Kume, Koichi Umemoto, and Yasuo Tomita, Appl. Phys. Lett. 124, 071901 (2024), doi: 10.1063/5.0186753

Posters presented at conferences:

• "From Talbot Effect to Structure Analysis of a Holographic Phase Grating" by Christian Puchberger at 71st Annual Meeting of the Austrian Physical Society ÖPG, Leoben, Austria (https://oepg2022.unileoben.ac.at/)

• "Neutron diffraction in the multi-wave regime: Experimental observation of the Pendellösung effect under low-coherence conditions" by Ismaele V. Masiello at FOMO 2022, Trieste, Italy (https://www.matterwaveoptics.eu/)

Talks given:

• "Experimental observation of the Pendellösung effect for neutrons under low-coherence conditions" by Juergen Klepp at FOMO 2022 (September 2022), Trieste, Italy (https://www.matterwaveoptics.eu/)

• "VCN interferometry: Some history and (near) future perspectives" by Juergen Klepp at the Second Workshop on UCN and VCN Sources at ESS (May 2023), Lund, Sweden (invited, https://indico.esss.lu.se/event/3195/)
  
  
• "Very cold neutron (VCN) interferometry: (Near) future perspectives" by Juergen Klepp at the Physics of quantum electronics (PQE) conference (January 2024), Utah, USA (invited, https://www.pqeconference.com/pqe-history)