
Accession Number : AD0857979
Title : Neutron Transport in a Spherical Subcritical Assembly with an External Neutron Source.
Descriptive Note : Master's thesis,
Corporate Author : AIR FORCE INST OF TECH WRIGHTPATTERSON AFB OH SCHOOL OF ENGINEERING
Personal Author(s) : Damm, Frederick C.
Report Date : JUN 1969
Pagination or Media Count : 103
Abstract : Neutron transport theory was used to predict resulting neutron distributions from an external neutron source in a spherical subcritical fissile assembly. A plane wavedelta function neutron source in time was assumed incident on the sphere containing fissionable material. Two methods of threegroup calculations in r, theta spherical geometry were used. A timespace integrated diffusion equation was solved for fluence (nvt) as a function of energy and position. Secondly, the Boltzmann equation was solved by the discrete ordinates S sub n method. Computer codes for both methods were written in Fortran IV for the IBM 7094 computer. In a sphere 14 cm in diameter, composed of U235 and aluminum, fission buildup from a fission spectrum source resulted in a total increase in neutron population of three times the source strength. A comparison of the results of the two methods is presented. (Author)
Descriptors : (*NEUTRON TRANSPORT THEORY, SHIELDING), NEUTRON FLUX, URANIUM, REACTOR FUELS, FISSION, DIFFUSION, ITERATIONS, PARTIAL DIFFERENTIAL EQUATIONS, COMPUTER PROGRAMS, THESES.
Subject Categories : Nuclear Radiation Shield, Protection & Safety
Radioactiv, Radioactive Wastes & Fission Prod
Fission Reactor Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE