Neutron scattering cross section measurements for ${}^{56}\mathrm{Fe}$

Elastic and inelastic differential cross sections for neutron scattering from ${}^{56}\mathrm{Fe}$ have been measured for several incident energies from 1.30 to 7.96 MeV at the University of Kentucky Accelerator Laboratory. Scattered neutrons were detected using a ${\mathrm{C}}_6{\mathrm{D}}_6$ liquid scintillation detector using pulse-shape discrimination and time-of-flight techniques. The deduced cross sections have been compared with previously reported data, predictions from evaluation databases ENDF, JENDL, and JEFF, and theoretical calculations performed using different optical model potentials using the talys and empire nuclear reaction codes. The coupled-channel calculations based on the vibrational and soft-rotor models are found to describe the experimental ($n,n_0$) and ($n,n_1$) cross sections well.

Figure 1

Typical TOF spectra containing events from the detection of both neutrons and $\gamma$ rays (red), neutrons only after pulse-shape discrimination (green), and also neutrons only after background subtraction (blue). In the top spectrum, peaks in the middle correspond to events from scattered neutrons while the largest peak on the right corresponds to events from the detection of prompt $\gamma$ rays.

Figure 2

Relative detector efficiency as measured from the angular distribution of the ${}^3\mathrm{H}(p,n){}^3\mathrm{He}$ reaction and a sixth-order polynomial fit.

Figure 3

The present experimental neutron elastic scattering differential cross sections for ${}^{56}\mathrm{Fe}$ (solid points) compared with previously reported data [4, 5, 7, 8, 9, 12] (open points), predictions from evaluation databases (curves, see key),, and theoretical calculations from talys.

Figure 4

The present experimental neutron differential cross sections for ${}^{56}\mathrm{Fe}$ for the inelastic scattering populating the 847-keV level (solid points) compared with previously reported data [5, 6, 7, 9, 10, 11, 12] (open points), predictions from evaluation databases (curves, see key), and theoretical calculations from talys.

Figure 5

Angle-integrated elastic (a) and inelastic scattering cross sections for excitation of the 847-keV (b) and 2085-keV (c) levels. Our experimental values (open points) are compared with existing data [4, 5, 10, 12, 32, 33] (solid points) and evaluations and theoretical calculations (curves).

Figure 6

Comparison between the present experimental cross sections (points) and coupled-channels calculations using talys with the default (dashed-dotted) and adjusted (dotted) parameters, and RIPL-3 parameter systematics obtained from Ref. [42] (solid).