Large-Scale Fabrication of Super-Mirror Reflection Surfaces for Neutron Guides

Fabrication of neutron super mirrors is a highly sophisticated technology requiring precise controlled layering of thousands of nanometer thin metal films. Neutron super mirrors are needed for guiding and focusing neutrons for diverse research areas including quantum materials, soft matter, materials and engineering, chemistry, and biosciences. There is a lack of domestic vendors of such mirrors. Current methods of fabrication are slow and capital intensive. To address this challenge, we propose to develop a novel Hot Wire Chemical Vapor Deposition method to fabricate multilayer neutron super mirrors. The proposed method is also less capital intensive and is estimated to save more than fifty percent in the overall cost of neutron mirror fabrication in raw materials, equipment requirements, and toxic exhaust gas treatment costs. Hot wire chemical vapor method can maintain high quality sharp interface features by minimizing interlayer diffusion of atoms. During Phase I, we demonstrated the design, assembly and working of a versatile Hot Wire Chemical Vapor Deposition reactor. Thin films of nickel and titanium deposited using the variation process of Hot Wire Atomic Layer Deposition was achieved. Characterization of the thin film morphology showed high quality films. Phase II of the project will study more detailed hot wire chemical vapor deposition coating recipes including variations in morphology of multilayers, substrates materials, precursor flow composition, pressure, temperature, and coating layer thickness, along with detailed techno-economic and lifecycle analyses. The development of such innovative, efficient and environmentally friendly technology will have many applications in other fields of micro electro-mechanical systems, solar array fabrication, protective coatings, flexible electronics, quantum computing and biomedical.