The Age of Fission Neutrons to Indium Resonance Energy in Graphite: Part II- Theory

Technical Report · Wed Apr 15 04:00:00 EST 1964

DOI:https://doi.org/10.2172/1968055· OSTI ID:1968055

Alter, Harry ^[1]

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1. North American Aviation, Inc., Canoga Park, CA (United States). Atomics International Div.

The Monte Carlo code TYCHE has been used to calculate the second, fourth, and sixth spatial moments of the slowing down density distribution at the indium resonance energy, for neutrons originating from a fission source at a point in an infinitely-extended graphite moderator. The effects of both inelastic scattering and anisotropy of elastic scattering have been included. These calculations can be compared with the moments of experimentally-measured distributions of neutron flux at the indium resonance energy, provided a suitable correction from slowing-down moments to flux moments is applied. The calculated value of the age, which is one-sixth of the second flux moment, is 307.4 ± 1.0 cm²; the fourth and sixth flux moments are 6.590 x 10⁶ cm⁴ and 4.006 x 10¹⁰ cm⁶, respectively. The corresponding experimental values are 307.8 ± 2.0 cm², 6.577 x 10⁶ cm⁴ and 3.843 x 10¹⁰ cm⁶. The calculated and measured values are seen to be in satisfactory agreement.

• Research Organization: North American Aviation, Inc., Canoga Park, CA (United States). Atomics International Div.
• Sponsoring Organization: US Atomic Energy Commission (AEC)
• DOE Contract Number: AT(11-1)-GEN-8
• OSTI ID: 1968055
• Report Number(s): NAA-SR--8684
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS