Neutron Cross Section Evaluation Group - Cross Sections for Transuranium Element Production
- Brookhaven National Laboratory (BNL), Upton, NY (United States)
An evaluation of cross sections useful for determining the production of transuranium elements is presented. The measured thermal cross sections and resonance integrals for the heavy elements beginning with U234 were collected. Resonance parameters reported in BNL-325 were used in a single level formalism to reconstruct the total and partial neutron cross sections as a function of energy for the nuclides U236, Np237, Pu238, Pu240, Pu241, Pu242, Am243, and Cm244. A single scattering radius, adjusted for best fit in the valleys between resonances, was used and a l/v background cross section added to account for the low energy tails of the unresolved resonances. Good fits to the measured total and partial cross sections were observed throughout the resolved resonance region for most nuclides, but strong resonance-resonance interference effects were noted for Pu241. An integral over energy of the product of the absorption or fission cross section and a 1/E flux from a low energy limit of 0.55 eV was calculated as a function of energy in the resolved resonance region. An extrapolation to high energies allowed comparison with measured resonance integrals. Good agreement between extrapolated resonance integrals and measurements was noted for all cases except Pu237 238nndNp. New information is reported for the capture integrals of Pu241, Am241, and Cm244, and the fission integral of Am241.
- Research Organization:
- Brookhaven National Laboratory (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP); US Atomic Energy Commission (AEC)
- DOE Contract Number:
- AT(30-2)-GEN-16
- NSA Number:
- NSA-20-044602
- OSTI ID:
- 4511543
- Report Number(s):
- BNL-982
- Country of Publication:
- United States
- Language:
- English
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