Neutron Capture Cross Section of Neptunium-237

Measurement and resonance analysis of the237Np neutron capture cross section

“…The experimental values in Table V correspond to the measurements of Hoffman et al [6], Weston and Todd [8], Kobayashi et al [9], and Scherbakov et al [10]. For the sake of clarity, the ratios reported in the table are illustrated in Fig.…”

“…Other authors have compared their results in selected energy intervals below 100 eV [8,10] and thus the same intervals have been chosen in this work. However, the good energy resolution of the n_TOF data allow investigating the average cross sections calculated from resonance parameters up to higher neutron energies and therefore two additional energy intervals have been included: 100-280 eV and 280-500 eV.…”

“…A detailed investigation of the results from previous capture [5][6][7][8][9][10][11], fission [6,12,13], and total [6,7,[12][13][14] cross section measurements reveals significant discrepancies between experiments. Indeed, the recommended 237 Np evaluations do not result from the combination of several data sets as it is always desirable; instead, individual data sets are selected for each reaction channel and each neutron energy range.…”

“…Indeed, the recommended 237 Np evaluations do not result from the combination of several data sets as it is always desirable; instead, individual data sets are selected for each reaction channel and each neutron energy range. In particular, in the resolved resonance region the neutron and capture widths in the JENDL-4.0 evaluation are from a single transmission measurement by Gressier et al [14] while the capture cross section in the unresolved resonance region is directly that from the measurement by Weston and Todd [8]. In the case of JEFF-3.1 and ENDF/B-VII.1 the resonance parameters range only up to 150 eV and are taken directly from the work of Paya [12].…”

“…In the case of JEFF-3.1 and ENDF/B-VII.1 the resonance parameters range only up to 150 eV and are taken directly from the work of Paya [12]. Only recently, a work by Noguere [15] has combined the most recent capture and transmission data; however, high-resolution data exist only up to 100 eV, with only one data set (Weston and Todd [8]) available between 10 and 100 eV. Therefore, the results above 100 eV are based only on transmission.…”