Neutron-induced fission cross sections simulated from (t,pf) results -: art. no. 024610

Neutron-induced fission cross sections on U-235 and U-235(m) targets in the incident neutron energy range E-n=0.1-2.5 MeV have been deduced from surrogate U-234(t,pf) measurements. The surrogate (t,pf) reaction is used to populate the same compound system as the (n,f) reaction before fission, and modeling is used to compensate for the difference in population mechanisms. The calculations presented in this paper improve on previous results by incorporating realistic angular momentum and parity distributions for the (t,p) channel, and by updating transmission-coefficient values used in the neutron-capture and emission contributions that compete with the fission process. The results are generally reliable within the 10% systematic uncertainties of the (t,pf) data.