²³⁵U(n,f), ²³³U(n,f) and ²³⁹Pu(n,f) prompt fission neutron spectra

New prompt fission neutron spectra (PFNS) matrices for the n+²³⁵U, n+²³³U, and n+²³⁹Pu systems are prepared. Present and previous PFNS shapes are drastically different from each other, the former being consistent with measured data base. A combined generalized least-squares fit of nth+²³⁵U, nth+²³³U, nth+²³⁹Pu, and ²⁵²Cf(sf) measured data base is accomplished. The solution of the longstanding problem of inconsistency of ²³⁵U integral data testing and differential prompt fission neutron spectra data (PFNS) is proposed. Similar problems for the n+²³³U and n+²³⁹Pu are envisaged, revealing arbitrary tweaking of relevant neutron cross sections. Fast ²³⁵U integral critical assemblies like Godiva or Flattop benchmarks are reproduced with the same accuracy as with the PFNS of the major data libraries. That reveals a rather delicate compensation effect, tracking the success of the distorted PFNS of the major data libraries to the excessive number of neutrons at energies of 1-3 MeV. Thermal assembly benchmarking reveals positive biases in k_eff which might be attributed to the influence of a soft energy tail of the present PFNS. For some of Valduc's LCT benchmarks biases in k_eff are less than 20 pcm. Fast ²³⁹Pu integral critical experiments like Jezebel reveal the influence of overestimated inelastic scattering for ²³⁹Pu, arbitrarily introduced previously to diminish the influence on the k_eff of the distortion of the PFNS.