Hauser-Feshbach fission fragment de-excitation with calculated macroscopic-microscopic mass yields

Journal Article · Thu Mar 15 00:00:00 EDT 2018 · Physical Review C

DOI:https://doi.org/10.1103/PhysRevC.97.034608· OSTI ID:1440483

Jaffke, Patrick John  ^[1]; Talou, Patrick ^[1]; Sierk, Arnold John ^[1]; Moller, Peter  ^[1]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

The Hauser-Feshbach statistical model is applied to the de-excitation of primary fission fragments using input mass yields calculated with macroscopic-microscopic models of the potential energy surface. We test the sensitivity of the prompt fission observables to the input mass yields for two important reactions, ²³⁵U (n_th, f) and ²³⁹Pu (n_th, f) , for which good experimental data exist. General traits of the mass yields, such as the location of the peaks and their widths, can impact both the prompt neutron and γ-ray multiplicities, as well as their spectra. Specifically, we use several mass yields to determine a linear correlation between the calculated prompt neutron multiplicity $$\bar{v}$$ and the average heavy-fragment mass $$\langle$$A_h$$\rangle$$ of the input mass yields ∂$$\bar{v}$$/∂ $$\langle$$A_h$$\rangle$$ = ± 0.1 (n / f )/u . The mass peak width influences the correlation between the total kinetic energy of the fission fragments and the total number of prompt neutrons emitted, $$\bar{v}_T$$ ( TKE ) . Finally, typical biases on prompt particle observables from using calculated mass yields instead of experimental ones are δ$$\bar{v}$$ = 4 % for the average prompt neutron multiplicity, δ$$\overline{M}_γ$$ = 1% for the average prompt γ-ray multiplicity, δ$$\bar{ε}$$ $$LAB\atop{n}$$ = 1 % for the average outgoing neutron energy, δ$$\bar{ε}_γ$$ = 1 % for the average γ-ray energy, and δ $$\langle$$TKE$$\rangle$$ = 0.4 % for the average total kinetic energy of the fission fragments.

• Research Organization: Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1440483
• Alternate ID(s): OSTI ID: 1426328
• Report Number(s): LA-UR-17-31000; PRVCAN; TRN: US1900748
• Journal Information: Physical Review C, Vol. 97, Issue 3; ISSN 2469-9985
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

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