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 WRIGHT-PATTERSON 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 wave-delta function neutron source in time was assumed incident on the sphere containing fissionable material. Two methods of three-group calculations in r, theta spherical geometry were used. A time-space 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 U-235 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