Date of Award
Neutron Radiography is a form of non-destructive testing that can be used instead or in conjunction with X-ray imaging to produce high resolution images for use in automotive, aerospace and tribology areas. Unlike x-ray imaging, neutrons interact with a materials nucleus allowing neutron radiography to be used with denser materials that are larger in atomic mass such as lead. This can be very useful in automotive, aerospace and tribology fields because denser materials are frequently used. Simplicity reliability and safety requirements must be considered for the design of this facility. This essay describes an engineering design for a neutron radiography facility to be built and used at the RINSC reactor to create detailed and high-resolution images for aerospace, automotive or tribology reasons. This project was sponsored by Low Alamos National Laboratory at the University of Rhode Island and performed by faculty and students in the mechanical and nuclear engineering program. A 3D scale model of each component has been created in Solidworks and combined to create a 3D assembly of the facility for proof of concept.
An apparatus for use in neutron radiography has a pneumatic shutter with a tri-layer composition to shield against neutron and gamma radiation escaping the beam port when not in inspection use. Following the shutter is a collimator made of a neutron absorbing material, in order to consolidate the neutron beam in an organized fashion towards the inspection stand and specimen. Attached to the collimator is a vacuum pump to minimize the moisture and other foreign elements that the neutrons could interact with. The inspection table incorporates three degrees of freedom, X, Z and theta to achieve a 2ft by 2ft desired inspection window. The neutrons passing through the specimen pass through a scintillating screen in the neutron converter, thus converting the neutrons into visible light to then be observed by a low light camera. Inside the neutron converter is a first surface mirror to reflect the visible light towards the camera. The interior of the neutron converter is dark as possible to amplify the visible light created by the scintillating screen, so the camera can produced a high resolution image. Lastly the neutron beam stopper is in place behind everything and is composed of concrete polyethylene to absorb the neutron beam.
Fuentes, Jonathan; Azzarto, Nick; and Lian, Nick, "Design of a Neutron Radiography Facility" (2019). Mechanical Engineering Capstone Design Projects. Paper 75.