Neutron Transport in a Spherical Subcritical Assembly with an External Neutron Source.
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1969
- Accession Number
- AD0857979
Entities
People
- Frederick C. Damm
Organizations
- Air Force Institute of Technology