2014/09/18 by J. P. Lestone, Lestone, J. P.
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Nuclear Theory (nucl-th) #nucl-th #physics.ins-det
paper · pdf · doi:10.48550/arxiv.1410.1769
11 pages, 7 figures, 1 table, Los Alamos National Laboratory report LA-UR-07-6090
arxiv created 2014/09/18 · openalex publication_date 2014/09/18 · arxiv updated 2014/10/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Many neutron transport Monte-Carlo codes can randomly sample fission neutron energies from a Watt spectrum. The quality of simulations depends on how well the Watt spectrum represents the true energy spectrum of the fission neutrons, and on one's choice of the Watt parameters a and b. The energy spectra of fission neutrons have been calculated and tabulated for the neutron induced fission of 235,238U and 239Pu as a function of incoming neutron energy by Madland using the Los Alamos Model. Each of these energy spectra are mapped into time-of-flight space and fitted with a Watt spectrum. A subroutine getab has been written to interpolate these results, so that Watt a and b parameters can be estimated for all incoming neutron energies up to ~16 MeV.