neutrons. PubMed Google Scholar. On the basis of the experimental results obtained, it is possible to say that the use of any high density concrete will lead to an increase in shielding cost in comparison with shielding of ordinary concrete (Table 3). Slow down neutrons (the same principle as the neutron moderation). Title: Barite concrete for 252Cf spontaneous neutron shielding based on Monte Carlo computation Author, co-author: Guembou Shouop, Cébastien Joel; BAK, Sang-In; NDONTCHUENG MOYO, Maurice; NGUELEM, Eric Jilbert; Strivay, David Abstract: Recently, neutron applications as neutron imaging widespread and safety issue related to high neutron penetration is still a concern in neutron industry. © 2021 Springer Nature Switzerland AG. sup4, pp. It was found that increasing barite proportion in the concrete increased the gamma attenuation coefficient while it decreased the neutron removal cross-section. Zaitsev, L.N., Komochkov, M.M. Three readings on each face of the samples from each site were measured, i.e. 1 at normal hitting by neutrons the concrete shielding Borated Polyethylene 30 is available in slabs, bricks, and cylinders. Immediate online access to all issues from 2019. Table I: Linear attenuation coefficients for different materials. A. N. Komarovskii, Construction of Nuclear Plants [in Russian] Moscow, Gosénergoizdat, 1961. Transparent. The attenuation lengths of concrete and iron for high energy neutrons above 20MeV were obtained from the 12C(n,2n) reaction of carbon, and the neutron spectra penetrated through the additional shield and on the target shield top were obtained from the 12C(n,2n), 27Al(n,α) and 209Bi(n, xn) reactions, and multi-moderator spectrometer. AN SSSR,” seriya fiz.,19. Deposited energy values per unit volume as a function of neutron energy were shown in Figure 4. Thermal-neutron flux measure- Note that the calculation can significantly underestimate absorption due to resonance effects, but resonant neutron absorption rarely occurs in powder diffraction measurements. V. P. Dzhelepov et al., “Izv. éksperim. 22-25. <>
i teor. The observed behavior of the penetrating neutrons in a concrete shield is accounted for by a simple theory making use of a calculated transport' cross section for fast neutrons. the neutrons with the energy of 1÷ 400 MeV for fitting of the data of neutron dose equivalent in concrete, example is given in Fig. %PDF-1.5
Concrete Streaming Streaming – Door Design Streaming – Labyrinth Contents 6 Shine Appendices ... u is the linear attenuation coefficient (e.g., cm-1). V. S. Kiselev et al., “Zh. Rev.,89, 724 (1953). In conclusion, the authors thank V. P. Dzhelepov and A. N. Komarovskii for their help in arranging the experiment. x���mO�0��W�w���D�~~�P@LtB�^M{��"uA A Hurst dosimeter was used to measure the fast-neutron dose rate. loaded Portland concrete has higher total absorption dose rate than 20% colemanite loaded concrete. Cheap. Tax calculation will be finalised during checkout. GEANT4 is being used to study neutron attenuation, and optimising the layers of shielding material to minimize thickness. i�~�NM����w?�w��[8>�/ϯ�ON�lqg���R���5p� P�"7��CK#��O���N��~�×����by�;�}(>p�@db�F�s j"=��N3L�eČ@�A��K�H��*���~������m�2S�4;�ݵH�Q��#$m���5s�c�m]��.^-;���w{���Y���r�>�M�Y�0� 573 (1955). Good neutron attenuation. Source terms and attenuation lengths for neutron attenuation in a concrete shield were calculated starting from experimental neutron… High energy neutron attenuation in concrete. endobj
Neutron Excitation Function – A plot of cross section vs neutron energy for a given neutron-target system. Much lower bremsstrahlung production than lead or bismuth when beta radiation is present. In this work, B4C is added into concrete as fine aggregates to test the attenuation properties by getting the attenuation coefficient of the concrete/ B4C. Since a proton and a neutron have almost identical masses, a neutron scatteringon a hydrogen nucleus can give up a … Appendix B: MCNP Code: Neutron Attenuation by Concrete 28 Appendix C: MCNP Code: Neutron Dispersion 31 Appendix D: MCNP Code: Both Dispersion and Attenuation Present 34 Appendix E: MATLAB code used to plot MCNP results 37 Appendix F: MATLAB code used to theoretically predict activations 39 References 41 3 An experiment was performed at tbe Lid Tank Shielding Facility to determine the dependence of the neutron attenuation of a structaral concrete shield on the amount and placement of water hydrogen throughout the shield. The effect of high temperature on neutron attenuation in concrete was determined. The equilibrium λ of neutrons in concrete is 72 g cm −2, which is close to the `mean' value of the three attenuation lengths for high-energy (120 g cm −2), mid-energy (55 g cm −2) and low-energy (30 g cm −2) neutrons used in SHIELD11. View Show abstract Although there is a negligible discrepancy (5%), Report issued by the Oak Ridge National Laboratory discussing the development of a high-density concrete. & Sychev, B.S. Borated & Pure Polyethylene Neutron Shielding. volume 12, pages558–561(1963)Cite this article. 2, 152 (1960). This is a preview of subscription content, log in to check access. The results have provided useful information about neutron attenuation lengths and the <>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>>
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