Neutron Capture to Fission Ratios in U ²³³ , U ²³⁵ , Pu ²³⁹

A new approach for cross section evaluations in the high energy region

“…7-9 also agree well with the available experimental data for the capture [38][39][40][41][42], (n, 2n) [43,44] and (n, 3n) [43,45] reactions, respectively.…”

Uranium-235 Neutron Capture Cross Section at keV Energies

“…To increase the total number of data points (especially at incident neutron energies higher than 300 keV), we add three measurements done after 1980 [14][15][16] and four older measurements including data points at neutron energies higher than 300 keV. [17][18][19][20] The information on systematic uncertainties reported in these additional seven measurements is not enough for the present analysis and we made an assumption that energy dependent uncertainties given by the authors are statistical and they have a large constant total systematic error of 3%. All the experimental data are obtained from the EXFOR database 21) in the form of value (ratio of 235 U neutron capture cross section to 235 U neutron fission cross section).…”

Measurement of neutron capture and fission cross sections of233U in the resonance region

“…The available data for this ratio present a dispersion of more than 25% due to the high uncertainties of the capture cross section [1,2]. For these experimental data little information is available on the measurement methods, types of detectors used, the neutron source, uncertainties as well as the energy ranges [3]- [7]. Fig.…”

“…Recent nuclear data sensitivity analysis [1,2] of the breeding of the thorium cycle, have shown that the fissile regeneration is dominated by uncertainties in the α ratio between the capture and fission cross section of 233 U. The available experimental data are at the present insufficient [3]- [7], and inconsistencies still exist among nuclear data libraries [8]. Therefore, new and accurate measurements for fission and neutron capture reactions of 233 U are required to improve the reliability of cross section data.…”