Event-by-event study of prompt neutrons from 239Pu(n,f)

Abstract

Employing a recently developed Monte Carlo model, we study the fission of 240Pu induced by neutrons with energies from thermal to just below the threshold for second chance fission. Current measurements of the mean number of prompt neutrons emitted in fission, together with less accurate measurements of the neutron energy spectra, place remarkably fine constraints on predictions of microscopic calculations. In particular, the total excitation energy of the nascent fragments must be specified to within 1 MeV to avoid disagreement with measurements of the mean neutron multiplicity. The combination of the Monte Carlo fission model with a statistical likelihood analysis also presents a powerful tool for the evaluation of fission neutron data. Of particular importance is the fission spectrum, which plays a key role in determining reactor criticality. We show that our approach can be used to develop an estimate of the fission spectrum with uncertainties several times smaller than current experimental uncertainties for outgoing neutron energies up to 2 MeV.

arXiv comment17 pages, 20 figures

References in corpus (4)

• Nuclear Ground-State Masses and Deformations
• Microscopic approach of fission dynamics applied to fragment kinetic energy and mass distributions in 238U
• Structure properties of ${}^{226}$Th and ${}^{256,258,260}$Fm fission fragments: mean field analysis with the Gogny force
• Calculation of fission observables through event-by-event simulation

Cited by in corpus (13)

• Error Estimates of Theoretical Models: a Guide
• Induced Fission of ${}^{240}$Pu within a Real-Time Microscopic Framework
• Description of Induced Nuclear Fission with Skyrme Energy Functionals: I. Static Potential Energy Surfaces and Fission Fragment Properties
• Fission Dynamics of 240Pu from Saddle-to-Scission and Beyond
• Event-by-event evaluation of the prompt fission neutron spectrum from 239Pu(n, f)
• Event-by-event study of neutron observables in spontaneous and thermal fission
• Hauser-Feshbach fission fragment de-excitation with calculated macroscopic-microscopic mass yields
• Neck Rupture and Scission Neutrons in Nuclear Fission
• Spatial orientation of the fission fragment intrinsic spins and their correlations
• Connection of four-dimensional Langevin model and Hauser-Feshbach theory to describe statistical decay of fission fragments
• New developments in fission studies within the time-dependent density functional theory framework
• Non-Markovian character and irreversibility of real-time quantum many-body dynamics
• A critical assessment of the current implementations of the Generator Coordinate Method