Energy dependence of $$\bar v$$ for fast-neutroin fission of U238

Gamma ray production in inelastic scattering of neutrons produced by cosmic muons in $^{56}$Fe

“…Data presented in Fig. 2 for 1238.3 keV gamma line show an apparent increase of relative intensities with different neutron energies between 6.3 MeV and 14.2 MeV, a trend that can be explained in terms of results reported by Savin et al [11]. Namely, the cross section for emission of 846.8 keV normalization line increases at energies below 3.5 MeV and remains independent of neutron energy at the higher incident energies.…”

“…2. It can be explained once again in terms of ex-perimental results of Savin et al [11]: the cross section for production of 1810.8 keV photons has maximum at about 4 MeV and at higher neutron energies uniformly decreases. Unfortunately, in the background spectra of the present study 1810.8 keV gamma line appears very weak and relative intensities were determined with large statistical uncertainties.…”

“…The possible exploration of chemical composition of planets and extraterrestrial materials [1] by analysis of gamma spectra emitted from the surface, renewed the interest for gamma ray production cross sections in stable nuclei [2,3]. The energy level structure of the stable 56 Fe has been studied extensively in the past via inelastic neutron scattering (INS) [4][5][6][7][8][9][10], and pertinent cross sections for the gamma ray production exist [8,11]. However, secondary neutrons produced by primary cosmic rays have much higher energies compared to reactor ones and cross sections for gamma ray production by the use of neutrons with energies up to 150 MeV were studied recently [12,13].…”

“…Reliable experimental studies [8,11] of cross sections for 56 Fe(n, n ′ γ) reaction have indicated that detected intensities of gamma lines depend on incident neutron energy, and it is to be expected that the same holds for relative intensities. Indeed, for incident neutron energies between 6.3 MeV and 14.2 MeV, relative intensity of 1238.3 keV gamma line changes by almost 80% [14,15].…”