Absolute measurement of the 242Pu neutron-capture cross section
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- North Carolina State Univ., Raleigh, NC (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Here, the absolute neutron-capture cross section of 242Pu was measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. The first direct measurement of the 242Pu(n,γ) cross section was made over the incident neutron energy range from thermal to ≈ 6 keV, and the absolute scale of the (n,γ) cross section was set according to the known 239Pu(n,f) resonance at En,R = 7.83 eV. This was accomplished by adding a small quantity of 239Pu to the 242Pu sample. The relative scale of the cross section, with a range of four orders of magnitude, was determined for incident neutron energies from thermal to ≈ 40 keV. Our data, in general, are in agreement with previous measurements and those reported in ENDF/B-VII.1; the 242Pu(n,γ) cross section at the En,R = 2.68 eV resonance is within 2.4% of the evaluated value. However, discrepancies exist at higher energies; our data are ≈30% lower than the evaluated data at En ≈ 1 keV and are approximately 2σ away from the previous measurement at En ≈ 20 keV.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-07NA27344; AC52-06NA25396
- OSTI ID:
- 1260476
- Alternate ID(s):
- OSTI ID: 1249662
- Report Number(s):
- LLNL-JRNL-677704; PRVCAN
- Journal Information:
- Physical Review C, Vol. 93, Issue 4; ISSN 2469-9985
- Publisher:
- APSCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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