A novel pyrolytic-graphite-on-silicon device for neutron monochromatization

0572670 - ÚJF 2024 RIV NL eng J - Journal Article
Freund, A. - Chen, C.-Y. - Crosby, M. - Farkas, Gergely - Kozak, B. - Krencisz, D. - Liu, X. - Mikula, Pavol
A novel pyrolytic-graphite-on-silicon device for neutron monochromatization.
Nuclear Instruments & Methods in Physics Research Section A. Roč. 1048, MAR (2023), č. článku 168012. ISSN 0168-9002. E-ISSN 1872-9576
R&D Projects: GA MŠMT LM2023057
Research Infrastructure: CICRR - 90241
Institutional support: RVO:61389005
Keywords : Neutron monochromators * Pyrolytic graphite * Bent perfect crystals * Dual focusing systems
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 1.4, year: 2022
Method of publishing: Limited access
https://doi.org/10.1016/j.nima.2023.168012

In the quest of improving neutron scattering instrumentation a new style of dynamically focusing monochro-mator is proposed where highly oriented pyrolytic graphite (HOPG) crystals are bonded on bendable single crystal silicon blades. This development followed a study of the elastic limit of HOPG that revealed serious technical difficulties when bending thin blades of this very fragile material to achieve dynamical focusing. The critical breakage thickness was found to be less than 0.1 mm for a radius of curvature of 1.5 m. The novel PG-on-Si (POSI) concept replaces the linear arrays of individually oriented HOPG pieces employed in existing devices. It facilitates the integration of two separate HOPG and Si monochromators into a single device. Mechanical tests, X-ray and neutron diffraction studies of the POSI system confirmed the feasibility of these single and dual monochromator designs that feature high performance and augmented functionality at reduced complexity and cost.
Permanent Link: https://hdl.handle.net/11104/0343276