Fission-product Yields from Photon-induced Fission of <sup>240</sup>Pu and Neutron-induced Fission of <sup>239</sup>Pu as a Function of Incident Energy
ORAL
Abstract
The Bohr Hypothesis, one of the most fundamental assumptions in nuclear fission theory, states that the decay of a compound nucleus with a given excitation energy, spin and parity is independent of its formation1. Using fission product yields (FPYs) as a sensitive probe, we have performed novel high-precision test of the combined effects of the entrance channel, spin and parity on the fission process. Two different reactions were used in a self-consistent manner to produce a compound 240Pu nucleus with the same excitation energy: neutron induced fission of 239Pu and photon-induced fission of 240Pu. The FPYs from these two reactions were measured using quasimonoenergetic neutron beams from the TUNL’s FN tandem Van de Graaff accelerator2 and quasimonenergetic photon beams from the HIGS facility. A comparison of the FPYs from 239Pu(n,f) at En=1.5 and 4.6 MeV with those from 240Pu(γ,f) at Eγ=8 and 11.2 MeV will be presented.
1 N. Bohr and J. A. Wheeler, “The Mechanism of Nuclear Fission.” Physical Review 56, 426 (1939).
2 M.E. Gooden et al., “Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV.” Nuclear Data Sheets 131, 319 (2016).
1 N. Bohr and J. A. Wheeler, “The Mechanism of Nuclear Fission.” Physical Review 56, 426 (1939).
2 M.E. Gooden et al., “Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV.” Nuclear Data Sheets 131, 319 (2016).
*This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.
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Presenters
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Jack A Silano
- Lawrence Livermore National Laboratory