Investigating the type of material and coating of neutron chopper blades on the amount of thermal neutron absorption

Document Type : Full length research Paper

Authors

1 1Department of Physics, Damghan University. Damghan, Iran

2 Department of Physics, Damghan University, Damghan, Iran

3 Nuclear Science and Technology Research Center, AEOI, Tehran, Iran

Abstract

Neutron choppers, which work with rotating blades and remove neutrons with unwanted energy, can allow neutrons with certain energy to pass through. In the design of a neutron velocity selector and the crucial role of these blades in its operation, simulation and experimental studies were performed to investigate the material and type of coating of the blades in relation to thermal neutron absorption. In this study, blades made of cadmium, aluminum, and carbon fiber with different coatings were exposed to thermal neutrons, and the neutron transmission was calculated using the MCNPX code. Based on the simulation results, blades with cadmium coatings and coatings of B4C, LiF, and H3BO3 with specific thicknesses were designed. The thermal neutron absorption of the constructed blades was measured in a thermal neutron flux from an Am-Be source using a BF3 detector. The results show that the cadmium blade without coating (1 mm thick), the aluminum blade (0.5 mm thick), and the carbon fiber blade (0.9 mm thick), both with B4C coatings, have the highest thermal neutron absorption values. The simulation and experimental results show that a B4C coating with a concentration of  is suitable for neutron velocity selector blades.

Keywords

Main Subjects


[1] R. Crawford, Neutron scattering instrumentation. A guide to future directions, (2001).
[2] J. Lu, P. Sabharwall, B. Heidrich, R. Christensen, Advanced manufacturing and instrumentation for neutron chopper design, Journal of Young Investigators, 38 (2020).
[3] R. Lowde, The principles of mechanical neutron-velocity selection, Journal of Nuclear Energy. Part A. Reactor Science, 11 (1960) 69-80. https://doi.org/10.1016/0368-3265(60)90017-7
[4] R.F. Álvarez-Estrada, M.L. Calvo, Neutron optics: fundamentals, Advances in Neutron Optics, CRC Press, (2019) 3-78.
[5] E. Fermi, J. Marshall, L. Marshall, A thermal neutron velocity selector and its application to the measurement of the cross section of boron, Physical Review, 72 (1947) 193. https://doi.org/10.1103/PhysRev.72.193
[6] H. Friedrich, V. Wagner, P. Wille, A high-performance neutron velocity selector, Physica B: Condensed Matter, 156 (1989) 547-549. https://doi.org/10.1016/0921-4526(89)90727-8
[7] A. Poutchkov, Optimization of velocity monochromators for low-power research reactors, Small angle neutron scattering, (2006) 83.
[8] A.P. Sh.Madadi, Design and construction of chopper spectrometer and thermal neutron spectrum measurement, University of Tehran, Tehran, (1998). [In Persian]
[9] R. Becker, S. Bunker, Method for depositing boron-rich coatings, Google Patents, (2005).
[10] D.C. Halverson, G.W. Billings, G.M. Johnston, High neutron absorbing refractory compositions of matter and methods for their manufacture, Google Patents, (1993).
[11] R. Lu, S. Chandrasekaran, W.L. Du Frane, R.L. Landingham, M.A. Worsley, J.D. Kuntz, Complex shaped boron carbides from negative additive manufacturing, Materials & Design, 148 (2018) 8-16. https://doi.org/10.1016/j.matdes.2018.03.026
[12] N.J. Carron, An introduction to the passage of energetic particles through matter, Taylor & Francis (2006). DOI 1201/9781420012378
[13] C.-M. Lin, Parameter optimisation of a vacuum plasma spraying process using boron carbide, Journal of thermal spray technology, 21 (2012) 873-881. https://doi.org/10.1007/s11666-012-9734-5
[14] A. Omidi, M. Tajik, E. Bayat, Design and construction of a neutron chopper and using the time-of -flight method for thermal neutron spectroscopy Journal of Nuclear Science, Engineering and Technology, In Press.  [In Persian] https://doi.org/10.24200/nst.2024.1544.2007