Neutron and Electron Beam Instrumentation (MSC P1R46-335)

75161-Current and future DOE neutron facilities, used for materials science research, lack the reliable, high-rotating-speed, large-aperture choppers needed to deliver maximum neutron fluxes at optimal band-width resolution. The traditional practice of using monolithic metallic rotors runs into problems due to their heavy weight, unattainable material strength, and high costs of fabrication and operation. Advanced composite materials, based on high-strength and light-weight fiber reinforcement technology, show promise, but further development is required. This project will combine focused risk-reduction research with detailed computer simulations of chopper design and fabrication procedures to take full advantage of the new materials. The risk-reduction research will address the operational constraints, neutron absorption/transmission requirements, and radiation effects associated with composite materials. The computer simulation will optimize the overall design and novel configurations that interface with the magnetic-bearings motors. The project will result in the design, fabrication, and testing of a chopper with an aperture of 750 mm2 and rotation speed at 36,000 rpm, parameters that have not been realized at any neutron spallation source in the world. Commercial Applications and Other Benefits as described by the awardee: High-performance, low-cost choppers should benefit virtually every beamline at existing and next-generation spallation neutron sources, including those under construction in the US, Japan, and UK. Mastering this technology would enable a US company to supply chopper devices to neutron centers all over the world. Furthermore, this technology could be extended and eventually applied to other neutron-beam filter and optical components that involve high-speed rotation.