NECTAR—A fission neutron radiography and tomography facility

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2011-09, Vol.651 (1), p.86-89
• Main Authors: Bücherl, T., Lierse von Gostomski, Ch, Breitkreutz, H., Jungwirth, M., Wagner, F.M.
• Format: Article
• Language: English
• Subjects: Activation; Beams (radiation); Fission; Gamma radiation; Gamma rays; MEDAPP; NECTAR; Neutron; Nuclear fission; Nuclear reactor components; Plates; Radiography; Tomography
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2011.01.058

NECTAR (Neutron Computerized Tomography and Radiography) is a versatile facility for radiographic and tomographic investigations as well as for neutron activation experiments using fission neutrons. The radiation sources for this facility are two plates of highly enriched uranium situated in the moderator vessel in FRM II. Thermal neutrons originating from the main fuel element of the reactor generate in these plates fast neutrons. These can escape through a horizontal beam tube without moderation. The beam can be filtered and manipulated in order to reduce the accompanying gamma radiation and to match the specific experimental tasks. A summary of the main parameters required for experimental set-up and (quantitative) data evaluation is presented. The (measured) spectra of the neutron and gamma radiations are shown along with the effect of different filters on their behavior. The neutron and gamma fluxes, dose rates, L/ D-ratios, etc. and the main parameters of the actually used detection systems for neutron imaging are given, too.