  Variation of fission neutron spectra of 240Pu (sf) and 240Pu (n, F) for E up
to 20 MeV predicted.Features of angle-integrated prompt fission neutron spectra
of 240Pu (n, F) stem from simultaneous analysis of data for 238U (n, F), 239Pu
(n, F) and available data on 240Pu (n, F) prompt fission neutron spectra.The
data on average energies of 240Pu (n, F) prompt fission neutron spectra support
the approach pursued in case of 238U (n, F) and 239Pu (n, F). Soft influence of
exclusive neutron spectra on prompt fission neutron spectra observed in case of
240Pu (n, F) and 240Pu (n, xnf) at E = 7-8 MeV. The largest relative amplitude
of exclusive neutron spectra 240Pu (n, xnf) is envisaged at E = 6-6.25 MeV.
Prompt fission neutron spectra of 240Pu (n, F) are harder than those of 238U
(n,F), but softer than prompt fission neutron spectra for 239Pu(n, F). 240Pu
(n, F) prompt fission neutron spectra 240Pu shape is rather close to that of
239Pu(n, F), though the contribution of pre-fission neutrons is relatively
higher. Exclusive neutron spectra (n, xnf) are consistent with (n,F) cross
sections of 237-240Pu(n, F), as well as neutron emissive spectra of 239Pu(n,
xn) at E = 14 MeV. We predict the exclusive pre-fission neutron spectra,
exclusive neutron spectra of (n,xn) reactions, average total kinetic energy TKE
of fission fragments and products, partials of of average prompt fission
neutron number and observed prompt fission neutron spectra.
