Key points are not available for this paper at this time.
The presence of 240Pu in nuclear fuels for reactors has resulted in high uncertainties in the results of reactor and nuclear transmutation calculations because of deficiencies in 240Pu-related nuclear data. Specifically for the prompt fission neutron spectrum (PFNS) of 240Pu, there is only one neutron-induced, (𝑛,𝑓), measurement at 0.85 MeV incident neutron energy and only one complete spontaneous fission, (sf), measurement. This limited availability of data does not sufficiently guide nuclear data evaluations of these quantities. Here, we report on a measurement of both the 240Pu(sf) and the 240Pu(𝑛,𝑓) PFNS, both over the emitted neutron energy range of 0.79–10.0 MeV, and from incident neutron energies of 1.0–20.0 MeV for the (𝑛,𝑓) reaction. Measurements were made with a hemispherical array of liquid scintillators at the high-energy Los Alamos Neutron Science Center white neutron source at the Weapons Neutron Research facility as part of the joint LANL-LLNL Chi-Nu experimental campaign to measure actinide fission neutron spectra. These measurements are the first of their kind, and provide clear experimental evidence for second-chance fission, third-chance fission, and pre-equilibrium neutron emission processes in neutron-induced fission of 240Pu, and are the first ever measurements above 1 MeV incident neutron energy.3 MoreReceived 16 February 2024Accepted 29 April 2024DOI:https://doi.org/10.1103/PhysRevC.109.064611©2024 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFissionNeutron physicsNuclear reactorsNucleon induced nuclear reactionsPhysical SystemsTransmutation & power generation with acceleratorsPropertiesA ≥ 220Nuclear Physics
Kelly et al. (Thu,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: