Speaker
Dr
Malgorzata Makowska
(Heinz Maier-Leibnitz Zentrum (MLZ), FRM II, Lichtenbergstr. 1 85748 Garching, Germany; Bavarian Research Institute of Experimental Geochemistry and Geophysics (BGI), University of Bayreuth, Germany)
Description
NECTAR [1] (neutron computed tomography and radiography) next to ANTARES is one of the two neutron imaging facilities located at the FRM II neutron source at Heinz Maier-Leibnitz Zentrum (MLZ). While Antares offers a broad range of versatile neutron imaging techniques utilizing a cold neutron spectrum, NECTAR, in contrast to most of the existing imaging beamlines, makes use of fission neutrons. This makes it a unique facility world-wide. The highly energetic spectrum with its mean energy at about 1.8 MeV is obtained via fission reactions taking place in the so-called converter plates placed in front of the window of the SR10 beam tube. The converter plates consist of 2 slabs of highly enriched uranium (93% 235U)-silicide with a total weight of 540 g. While the converter plates are not in the ‘working position’, a thermal neutron beam is available [2].
Due to the possibility of switching between fission and thermal spectra, NECTAR can be used for a broad variety of applications. The non-destructive inspection performed by neutron radiography and tomography using these two ranges of neutron energy can provide complementary information about the investigated objects. Penetration depth of fission neutrons is much higher as compared to cold or thermal neutrons, and thus gives more insight in large objects and samples containing strongly attenuating elements. In contrast, thermal neutrons provide a much better spatial resolution while still showing higher penetration depth than the cold neutrons available at ANTARES. Thus, due to high penetration depths, NECTAR is a well-suited instrument for investigation of inner structure of large, i.e. archaeological or paleontological objects. Because of the high sensitivity to light elements many applications are related to hydrogen or ammonia storage systems [3,4] and observation of water distribution in e.g. large wooden samples [5].
Neutron imaging capabilities and specification of the NECTAR facility as well as examples of typical applications will be presented.
1. Bücherl, T. & Söllradl, S. NECTAR: Radiography and tomography station using fission neutrons. J. large-scale Res. Facil. JLSRF 1, A19 (2015).
2. Mühlbauer, M. J. et al. The Thermal Neutron Beam Option for NECTAR at MLZ. Phys. Procedia 88, 148–153 (2017).
3. Börries, S. et al. Optimization and comprehensive characterization of metal hydride based hydrogen storage systems using in-situ Neutron Radiography. J. Power Sources 328, 567–577 (2016).
4. Börries, S. et al. Scattering influences in quantitative fission neutron radiography for the in situ analysis of hydrogen distribution in metal hydrides. Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 797, 158–164 (2015).
5. Bücherl, T. & Lierse von Gostomski, C. Real-time radiography at the NECTAR facility. Nucl. Instruments Methods Phys. Res. Sect. A Accel. Spectrometers, Detect. Assoc. Equip. 651, 175–179 (2011).
Primary author
Dr
Malgorzata Makowska
(Heinz Maier-Leibnitz Zentrum (MLZ), FRM II, Lichtenbergstr. 1 85748 Garching, Germany; Bavarian Research Institute of Experimental Geochemistry and Geophysics (BGI), University of Bayreuth, Germany)
Co-authors
Dr
Martin Mühlbauer
(Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1 85748 Garching, Germany; Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany)
Dr
Michael Schulz
(Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1 85748 Garching, Germany)
Dr
Thomas Bücherl
(Technische Universität München, ZTWB Radiochemie München RCM, Walther-Meissner-Str. 3, 85748 Garching, Germany)
