Characterization of a neutron imaging setup at the INES facility

Nondestructive Testing Methods and New Applications, 2012

Applied Radiation and Isotopes, 2010

The aims of this research are to study properties of a neutron imaging plate (NIP) and to test it for use in nondestructive testing (NDT) of materials. The experiments were carried out by using a BAS-ND 2040 Fuji NIP and a neutron beam from the Thai Research Reactor TRR-1/M1. The neutron intensity and Cd ratio at the specimen position were approximately 9 Â 10 5 ns/cm 2 s and 100 respectively. It was found that the photostimulated luminescence (PSL) readout of the imaging plate was directly proportional to the exposure time and approximately 40 times faster than the conventional NR using Gd converter screen/X-ray film technique. The sensitivities of the imaging plate to slow neutron and to Ir-192 gamma-rays were found to be approximately 4.2 Â 10 À 3 PSL/mm 2 per neutron and 6.7 Â 10 À 5 PSL/mm 2 per gamma-ray photon respectively. Finally, some specimens containing light elements were selected to be radiographed with neutrons using the NIP and the Gd converter screen/X-ray film technique. The image quality obtained from the two recording media was found to be comparable.

2017

Research is one of the three principal activities of a museum, besides education and conservation of the collections. All three have to be understood in the widest possible sense. Scientific research on the objects would in turn only represent a relatively small part of a museum's overall research activities, the focus being usually on historical, art historical, archaeological or other research directly in line with the museum's subject area. Neutron imaging and analysis of cultural artefacts are relatively new methods and only represent therefore a marginal technique on the fringe of a museum's activities. Why would under these circumstances neutron imaging be interesting to a museum? This paper presents examples from the Geneva Ethnographic Museum illustrating how looking inside an object contributes to our understanding of the museum's collections, and where, despite the exceptional logistical effort required for the analysis, neutron imaging becomes important or...

Neutron radiography systems based on Gd, Dy and In metallic foils and X-ray films have been used at this centre since early seventies for various NDT and R&D work in nuclear, defense and aerospace industries. In recent years use of digital detection systems such as neutron scintillator and CCD based imaging systems and photostimulated luminescence based phosphor imaging plate systems have been introduced in our work. This has enabled to achieve higher sensitivities and dynamic ranges of recording radiographs with acceptable spatial resolution. These new systems provide digital image information and are more convenient for quantitative evaluations. At BARC these new techniques have been used in variety of radiography techniques such as conventional neutron radiography (NR), neutron induced beta radiography (NIBR), hydrogen sensitive epithermal neutron radiography (HYSEN) using Apsara, CIRUS and Dhruva reactors as neutron sources. The details of the work done are described in this paper.

M. A. Stanoyev-Perreira, J. G. Marques, J. P. Santos, M. I. Prudencio, C. I. Burbidge, 2013

Neutron imaging techniques are non-destructive tools that can help to understand the processes involved in manufacturing and restoration of cultural heritage artefacts. The interaction of neutrons with matter is markedly different from the interaction of other types of radiation, enhancing features where light elements are involved. Imaging of relative levels of neutron absorption is based on photography of scintillations produced in a ZnS screen doped with LiF, where Li is used as a neutron to charged particle converter. In this work we present studies made in the Portuguese Research Reactor applied to the characterization of restorations with resin, absorption of natural oils, and water retention.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2010

Improved spatial detector resolution is exploited for engineering and geology, e.g., for the investigation of boron distribution in steel, consolidated aspects of building materials, and grain analysis in feldspar. The strengths and limitations of the upgraded instrument are evaluated in the context of these projects. First promising results have been obtained and will extend the range of applications for the neutron imaging beam-line at the Atomic Institute in Vienna.

Mediterranean Archaeology and Archaeometry

Neutron imaging techniques are non-destructive tools that can help to understand the processes involved in manufacturing and restoration of cultural heritage artefacts. The interaction of neutrons with matter is markedly different from the interaction of other types of radiation, enhancing features where light elements are involved. Imaging of relative levels of neutron absorption is based on photography of scintillations produced in a ZnS screen doped with LiF, where Li is used as a neutron to charged particle converter. In this work we present studies made in the Portuguese Research Reactor applied to the characterization of restorations with resin, absorption of natural oils, and water retention.

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004

For many years, the major detection system for neutron radiography consisted in an X-ray film, where the conversion from neutrons to detectable radiation was made with a metallic layer of Gd, Dy or In. With this method, high spatial resolution was achieved, only limited by the beam properties of the radiography facilities.

Journal of Imaging, 2018

Neutron Imaging is ideally suited for applications in cultural heritage even at small reactors with moderate image resolution. However, recently, high resolution imaging is being increasingly used for advanced studies, especially in paleontology. The special contrast for hydrogen and between neighboring elements in the periodic system allows for new applications that are not accessible for X-rays, like organic material in enclosed containers made of ceramics or metals, fossilized bones in chalk rock or in ferrous “red” beds, and even for animal and hominid teeth. Fission neutrons permit the examination of large samples that otherwise show large attenuation for thermal neutrons.

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 2005

The design objective of the thermal neutron radiography facility at the National Institute of Standards and Technology (NIST) Center for Neutron Research was to provide a large beam diameter and a high fluence rate in order to produce images of dynamic systems. A thermal neutron beam with a 14 cm diameter thimble was chosen. The beam was initially filtered by a 10 cm thick single crystal bismuth filter cooled with liquid nitrogen. The beam exiting the port is shaped using either a 1 cm or 2 cm diameter pinhole to form a uniform high fluence rate beam at the sample. The resulting neutron beam at the sample has an L/D ratio of 280 with a fluence rate of 1.84 Â 10 7 cm À2 s À1 and 560 with a fluence rate of 4.75 Â 10 6 cm À2 s À1 uniformly spread over a 26 cm diameter beam. To capture the neutron beam image a scintillator and CCD camera is used. The current neutron camera system is limited to a 2.5 s frame rate; however, a high frame rate detector system based on amorphous silicon will allow frame rates to meet the design goal. Samples can be rotated and translated in situ for radiography and tomography applications. This facility became operational in early 2003. Since then the facility has been translated backwards by E2.13 m and 5 cm of bismuth was added to the filter. The design of this facility and the impact of the later changes are discussed. r