Review of the neutron capture process in fission reactors

Abstract

The importance of the neutron capture process and the status of the more important cross section data are revieved. The capture in fertile and fissile nuclei is considered. For thermal reactors the thermal to epithermal capture ratio for 238 U and 232 Th remains a problem though some improvements were made with more recent measurements. The capture cross section of 238 U in the fast energy range remains quite uncertain and a long standing discrepancy for the calculated versus experimental central reaction rate ratio C28/F49 persists. Capture in structural materials, fission product nuclei and the higher actinides is also considered.

Total neutron cross section for181Ta

“…[7], by using this information we obtain total neutron cross section for 181 Ta in agreement with measurements Refs. [9][10][11]. We showed consistency of calculated cross sections for the correction for both absorbers.…”

“…(b) Total neutron cross sesction for 181 Ta, present data are compared with previosly published data Refs. [9][10][11].…”

“…4(b) There are few publications for neutron total cross section at 181 Ta in fast energy region that we compare our results with, Refs. [9][10][11]. Experiments done by Martin [9] and Foster [10] have high resolution, however, there is a systematic shift, Martin's data are systematically higher than data given by Foster.…”

“…Experiments done by Martin [9] and Foster [10] have high resolution, however, there is a systematic shift, Martin's data are systematically higher than data given by Foster. Furthermore data given by Poenitz [11] has low energy resolution. We did not want to judge who from Foster or Martin has better data, we checked how much are we in agreement with every of them.…”