Journal of large-scale research facilities, 1, A18 (2015) http://dx.doi.org/10.17815/jlsrf-1-43 Published: 19.08.2015 MEDAPP: Fission neutron beam for science, medicine, and industry Heinz Maier-Leibnitz Zentrum Technische Universität München Instrument Scientists: - Christoph Genreith, Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Garching, Germany, phone: +49(0) 89 289 14756, email: christoph.genreith@frm2.tum.de Abstract: The instrument MEDAPP (Medical Applications), operated by the Technische Universität München, and the respective irradiation position are located at the world-wide unique fast neutron beam tube SR10 to which a uranium converter is attached. Thus, the instrument is operated with unmoderated �ssion neutrons and can be used for a broad variety of applications. For selected tasks, an alternative use with thermal neutrons is possible. 1 Introduction MEDAPP is an instrument primarily built for the medical treatment of malignant tumours; but the irra- diation room (see Figure 1 and 2) can also be used for general purposes, e.g. for biological research and technical irradiations. Due to their energy spectrum, fast reactor neutrons have the highest biological e�ectiveness of clinical neutron beams used in cancer treatment, comparable only to the e�ectiveness of heavy ions. This advantage comes at the expense of penetration depth in tissue, which - due to the relatively low energy of 2 MeV - limits the application of fast reactor neutrons to near-surface tumours, typically recurrent breast tumours and melanomas. The particularly large beam cross-section of SR10 allows the irradiation of rather large objects, such as groups of cell culture �asks or complete elec- tronic devices. In addition, the FaNGas (Fast Neutron Gamma Spectrometry) instrument, consisting of a movable shielded HPGe detector system, can be installed within the MEDAPP irradiation chamber to directly measure gamma radiation emitted, e.g., in (n,n’), (n,2n), (n,p), and (n,α ) reactions and for non-destructive qualitative elemental analysis. 1 http://jlsrf.org/ http://dx.doi.org/10.17815/jlsrf-1-43 https://creativecommons.org/licenses/by/4.0/ Journal of large-scale research facilities, 1, A18 (2015) http://dx.doi.org/10.17815/jlsrf-1-43 Figure 1: The irradiation room of MEDAPP (Copyright by W. Schürmann, TUM). 2 Typical Applications • Neutron medical treatment of malign tumours • Biological dosimetry, e.g., irradiations of cell cultures • Irradiations of electronic components (also on-line tests) • Fundamental physics • In beam gamma spectrometry 3 Technical Data 3.1 Neutron source • Converter facility at FRM II: consisting of 2 plates of uranium-silicide (93 % 235U, total 540 g) 3.2 Neutron spectrum • Fission spectrum: Mean energy: 1.9 MeV Flux: up to 7 · 108 n cm-2 s-1 (depending on �lter used) • Thermal spectrum of the D2O moderator (without converter): Mean energy: 28 meV Flux: ca. 2 · 109 n cm-2 s-1 3.3 Collimation • Multi-leaf collimator, individually adjustable up to 27 cm x 19 cm. 2 http://dx.doi.org/10.17815/jlsrf-1-43 https://creativecommons.org/licenses/by/4.0/ http://dx.doi.org/10.17815/jlsrf-1-43 Journal of large-scale research facilities, 1, A18 (2015) Figure 2: Schematic drawing of the facilities MEDAPP and NECTAR (Heinz Maier-Leibnitz Zentrum, 2015) at beam tube SR10. 3.4 Sample space • Max. 40 cm x 30 cm 3.5 Detection systems • Ionisation chambers for dosimetry in custom-made phantoms • 50 %-HPGe detection system shielded with PE, B4C, and Pb • Custom systems can temporarily be installed by users References Heinz Maier-Leibnitz Zentrum. (2015). Nectar: radiography and tomography station using �ssion neutrons. Journal of large-scale research facilities, 1, A19. http://dx.doi.org/10.17815/jlsrf-1-45 3 http://dx.doi.org/10.17815/jlsrf-1-43 http://dx.doi.org/10.17815/jlsrf-1-45 https://creativecommons.org/licenses/by/4.0/ Introduction Typical Applications Technical Data Neutron source Neutron spectrum Collimation Sample space Detection systems