Download or read book An Improved Elastic and Nonelastic Neutron Transport Algorithm for Space Radiation written by Martha S. Clowdsley and published by . This book was released on 2000 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: In addition, a high-energy bidirectional neutron source based on a formula by Ranft showed even further improvement of the fluence results over previous results near the front of the water target where diffusion out the front surface is important. Effects of improved interaction cross sections are modest compared with the addition of the high-energy bidirectional source terms.
Download or read book An Improved Elastic and Nonelastic Neutron Transport Algorithm for Space Radiation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-27 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: A neutron transport algorithm including both elastic and nonelastic particle interaction processes for use in space radiation protection for arbitrary shield material is developed. The algorithm is based upon a multiple energy grouping and analysis of the straight-ahead Boltzmann equation by using a mean value theorem for integrals. The algorithm is then coupled to the Langley HZETRN code through a bidirectional neutron evaporation source term. Evaluation of the neutron fluence generated by the solar particle event of February 23, 1956, for an aluminum water shield-target configuration is then compared with MCNPX and LAHET Monte Carlo calculations for the same shield-target configuration. With the Monte Carlo calculation as a benchmark, the algorithm developed in this paper showed a great improvement in results over the unmodified HZETRN solution. In addition, a high-energy bidirectional neutron source based on a formula by Ranft showed even further improvement of the fluence results over previous results near the front of the water target where diffusion out the front surface is important. Effects of improved interaction cross sections are modest compared with the addition of the high-energy bidirectional source terms.Clowdsley, Martha S. and Wilson, John W. and Heinbockel, John H. and Tripathi, R. K. and Singleterry, Robert C., Jr. and Shinn, Judy L.Langley Research CenterNEUTRON SOURCES; ALGORITHMS; PARTICLE INTERACTIONS; SHIELDING; BOLTZMANN TRANSPORT EQUATION; RADIATION PROTECTION; EXTRATERRESTRIAL RADIATION; ELASTIC PROPERTIES; WATER; THEOREMS; TARGETS; SOLAR STORMS; SOLAR FLARES; SOLAR CORPUSCULAR RADIATION; RADIATION TRANSPORT; MONTE CARLO METHOD...
Download or read book An Improved Neutron Transport Algorithm for Space Radiation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-27 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A low-energy neutron transport algorithm for use in space radiation protection is developed. The algorithm is based upon a multigroup analysis of the straight-ahead Boltzmann equation by using a mean value theorem for integrals. This analysis is accomplished by solving a realistic but simplified neutron transport test problem. The test problem is analyzed by using numerical and analytical procedures to obtain an accurate solution within specified error bounds. Results from the test problem are then used for determining mean values associated with rescattering terms that are associated with a multigroup solution of the straight-ahead Boltzmann equation. The algorithm is then coupled to the Langley HZETRN code through the evaporation source term. Evaluation of the neutron fluence generated by the solar particle event of February 23, 1956, for a water and an aluminum-water shield-target configuration is then compared with LAHET and MCNPX Monte Carlo code calculations for the same shield-target configuration. The algorithm developed showed a great improvement in results over the unmodified HZETRN solution. In addition, a two-directional solution of the evaporation source showed even further improvement of the fluence near the front of the water target where diffusion from the front surface is important.Heinbockel, John H. and Clowdsley, Martha S. and Wilson, John W.Langley Research CenterNEUTRONS; ALGORITHMS; RADIATION PROTECTION; MATHEMATICAL MODELS; APPLICATIONS PROGRAMS (COMPUTERS); EXTRATERRESTRIAL RADIATION; BOLTZMANN TRANSPORT EQUATION; FLUENCE; WATER; MONTE CARLO METHOD; ENERGY SPECTRA; SOLAR FLARES...
Download or read book An Improved Neutron Transport Algorithm for Space Radiation written by John H. Heinbockel and published by . This book was released on 2000 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Natural and Induced Environment in Low Earth Orbit written by and published by . This book was released on 2002 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mars Transportation Environment Definition Document written by M. Alexander and published by . This book was released on 2001 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of Deterministic Transport Methods for Low Energy Neutrons for Shielding in Space written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-24 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transport of low energy neutrons associated with the galactic cosmic ray cascade is analyzed in this dissertation. A benchmark quality analytical algorithm is demonstrated for use with BRYNTRN, a computer program written by the High Energy Physics Division of NASA Langley Research Center, which is used to design and analyze shielding against the radiation created by the cascade. BRYNTRN uses numerical methods to solve the integral transport equations for baryons with the straight-ahead approximation, and numerical and empirical methods to generate the interaction probabilities. The straight-ahead approximation is adequate for charged particles, but not for neutrons. As NASA Langley improves BRYNTRN to include low energy neutrons, a benchmark quality solution is needed for comparison. The neutron transport algorithm demonstrated in this dissertation uses the closed-form Green's function solution to the galactic cosmic ray cascade transport equations to generate a source of neutrons. A basis function expansion for finite heterogeneous and semi-infinite homogeneous slabs with multiple energy groups and isotropic scattering is used to generate neutron fluxes resulting from the cascade. This method, called the FN method, is used to solve the neutral particle linear Boltzmann transport equation. As a demonstration of the algorithm coded in the programs MGSLAB and MGSEMI, neutron and ion fluxes are shown for a beam of fluorine ions at 1000 MeV per nucleon incident on semi-infinite and finite aluminum slabs. Also, to demonstrate that the shielding effectiveness against the radiation from the galactic cosmic ray cascade is not directly proportional to shield thickness, a graph of transmitted total neutron scalar flux versus slab thickness is shown. A simple model based on the nuclear liquid drop assumption is used to generate cross sections for the galactic cosmic ray cascade. The ENDF/B V database is used to generate the total and scattering cross sections for neutrons in a...
Download or read book The Foundations of Neutron Transport Theory written by Richard K. Osborn and published by Routledge. This book was released on 1966 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Methods of Neutron Transport written by Elmer Eugene Lewis and published by Wiley-Interscience. This book was released on 1984 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stochastic Neutron Transport written by Emma Horton and published by Springer Nature. This book was released on 2023-12-17 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph highlights the connection between the theory of neutron transport and the theory of non-local branching processes. By detailing this frequently overlooked relationship, the authors provide readers an entry point into several active areas, particularly applications related to general radiation transport. Cutting-edge research published in recent years is collected here for convenient reference. Organized into two parts, the first offers a modern perspective on the relationship between the neutron branching process (NBP) and the neutron transport equation (NTE), as well as some of the core results concerning the growth and spread of mass of the NBP. The second part generalizes some of the theory put forward in the first, offering proofs in a broader context in order to show why NBPs are as malleable as they appear to be. Stochastic Neutron Transport will be a valuable resource for probabilists, and may also be of interest to numerical analysts and engineers in the field of nuclear research.
Download or read book Mathematical Topics In Neutron Transport Theory New Aspects written by Mustapha Mokhtar Kharroubi and published by World Scientific. This book was released on 1997-12-18 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents some recent mathematical developments about neutron transport equations. Several different topics are dealt with including regularity of velocity averages, spectral analysis of transport operators, inverse problems, nonlinear problems arising in the stochastic theory of neutron chain fissions, compactness properties of perturbed of c0-semigroups in Banach spaces with applications to transport theory, Miyadera perturbations of c0-semigroups in Banach spaces with applications to singular transport equations, a thorough analysis of the leading eigenelements of transport operators and their approximation, scattering theory. Besides the new problems addressed in this book a unification and extension of the classical spectral analysis of neutron transport equations is given.
Download or read book An Introduction to Neutron Transport Theory written by J. H. Tait and published by . This book was released on 1965 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time dependent Neutron Transport with Elastic Scattering written by Mieczysław Borysiewicz and published by . This book was released on 1967 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Space Reactor System Components written by Shannon M. Bragg-Sitton and published by . This book was released on 2004 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Nuclear Engineering written by Dan Gabriel Cacuci and published by Springer Science & Business Media. This book was released on 2010-09-14 with total page 3701 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an authoritative compilation of information regarding methods and data used in all phases of nuclear engineering. Addressing nuclear engineers and scientists at all levels, this book provides a condensed reference on nuclear engineering since 1958.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-04 with total page 1082 pages. Available in PDF, EPUB and Kindle. Book excerpt:
