THE THERMAL NEUTRON SPECTRUM IN A FINITEMASS MEDIUM.

Abstract

The distribution of neutrons at thermal energies in a monatomic Maxwellian gas is determined. Spectra are found in various mass media and for varying amounts of absorption by numerically solving Corngold's higher-order gas equation; a result that is new. From the spectra obtained the average neutron velocity is found and the thermal diffusion length squared is calculated. Using this method and a neutron age from a moments method calculation, the migration area in selected real nuclides is determined. The deviations from Maxwellian of the thermal neutron spectra are used to determine the energy at which a neutron becomes thermal. This effective thermal transition energy, E*, is found for media of various mass with varying amounts of absorption. The neutron thermal spectrum is found to be generally non-Maxwellian for values of the absorption parameter greater than 0.01.

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1965
Accession Number
AD0621119

Entities

People

  • Ernest Park Sims

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption
  • Diffusion
  • Mass Media
  • Media
  • Neutron Age
  • Neutron Spectrum
  • Neutrons
  • Reactor Lattice Parameters
  • Spectra
  • Thermal Diffusion
  • Thermal Neutrons

Fields of Study

  • Physics

Readers

  • Molecular Photonics/Laser Physics
  • Solar Physics
  • Thermal Physics or Thermal Science.