Neutron guide shielding for the BIFROST spectrometer at ESS
| Autor: | Carsten P. Cooper-Jensen, E. B. Klinkby, Kim Lefmann, Mads F. Bertelsen, Konstantins Mantulnikovs |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
inorganic chemicals
History Physics::Instrumentation and Detectors Astrophysics::High Energy Astrophysical Phenomena Nuclear Theory Cosmic ray Accelerator Physics and Instrumentation Education Nuclear physics chemistry.chemical_compound Optics Neutron Nuclear Experiment Background radiation Physics integumentary system Spectrometer business.industry technology industry and agriculture Acceleratorfysik och instrumentering Boron carbides Neutron temperature Computer Science Applications chemistry biological sciences Electromagnetic shielding Measuring instrument lipids (amino acids peptides and proteins) business |
| Zdroj: | Mantulnikovs, K, Bertelsen, M, Cooper-Jensen, C P, Lefmann, K & Klinkby, E B 2016, Neutron guide shielding for the BIFROST spectrometer at ESS . in VI European Conference on Neutron Scattering (ECNS2015) ., 012027, IOP Publishing, Journal of Physics: Conference Series (Online), vol. 746, 6th European Conference on Neutron Scattering, Zaragoza, Spain, 30/08/2015 . https://doi.org/10.1088/1742-6596/746/1/012027 Mantulnikovs, K, Bertelsen, M, Cooper-jensen, C P, Lefmann, K & Klinkby, E B 2016, ' Neutron guide shielding for the BIFROST spectrometer at ESS ', Journal of Physics-Conference Series, vol. 746, no. 1, 012027 . https://doi.org/10.1088/1742-6596/746/1/012027 |
| DOI: | 10.1088/1742-6596/746/1/012027 |
| Popis: | We report on the study of fast-neutron background for the BIFROST spectrometerat ESS. We investigate the effect of background radiation induced by the interaction of fast neutrons from the source with the material of the neutron guide and devise a reasonable fast, thermal/cold neutron shielding solution for the current guide geometry using McStas and MCNPX. We investigate the effectiveness of the steel shielding around the guide by running simulations with three different steel thicknesses. The same approach is used to study the efficiencies of the steel wall a flat cylinder pierced by the guide in the middle and the polyethylene layer. The final model presented here has a 3 cm thick steel shielding around the guide, 30 cm of polyethylene around the shielding, two 5 mm thick B4C layers and a steel wall at position Z = 38 m, being 1 m thick and 10 m in radius. The final model finally proves that it is sufficient to bring the background level below the cosmic neutron rate, which defines an order of magnitude of the lowest obtainable background in the instruments. |
| Databáze: | OpenAIRE |
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