Evaluation of Neutron Nuclear Data on Arsenic-75 for JENDL-4

Abstract

Neutron nuclear data on 75 As have been evaluated for the evaluated nuclear data library JENDL-4 in the energy region from 10 À5 eV to 20 MeV. The thermal capture cross section was updated by considering recent measurements. The statistical model was applied to calculate the cross sections above the resolved resonance region. In the calculation, coupled-channel optical model parameters were used for neutrons. Pre-equilibrium and direct-reaction processes were taken into account in addition to the compound process. The present calculations are almost consistent with available experimental data. The measured leakage neutron spectrum is well reproduced by the presently evaluated data at 14 MeV.

Measurement and modeling of proton-induced reactions on arsenic from 35 to 200 MeV

“…It was therefore necessary to manually create a coupling scheme to see whether this has an effect on final results. Yet, the level scheme of 75 As does not present any ideal vibrational or rotational bands for coupling and its deformation is very likely either soft vibrational or soft rotational [102,103].…”

“…Elsewhere, this treatment for adjusting the global spherical optical model by a CC approach to implement a deformed optical model for 75 As calculations has been used in Shibata et al [103] and Kawano [102]. The Shibata et al [103] work is an evaluation of neutron nuclear data on 75 As up to 20 MeV for JENDL-4 and uses a similar rotational coupling scheme to the one presented here but substitutes the 5/2 − level at 279.543 keV with a 5/2 − level at 572.41 keV. Shibata et al [103] uses the quadrupole deformation parameter β 2 = −0.19 within a rigid-rotator model.…”

“…The Shibata et al [103] work is an evaluation of neutron nuclear data on 75 As up to 20 MeV for JENDL-4 and uses a similar rotational coupling scheme to the one presented here but substitutes the 5/2 − level at 279.543 keV with a 5/2 − level at 572.41 keV. Shibata et al [103] uses the quadrupole deformation parameter β 2 = −0.19 within a rigid-rotator model. In their evaluation, they found it necessary to additionally tune the matrix element parameter as well as the pickup and knockout contributions for their pre-equilibrium model relevant to the residual product cross sections of (n,γ), (n,p), (n,2n), and (n,α).…”

Cross-section calculations of (n,2n) and (n,p) reactions for 69,71Ga and 75As target nuclei up to 20 MeV

“…Arsenic (As) is a chemical element with atomic number 33 occurring in many minerals. Arsenic is known as a fission product and is also important for nuclear energy applications material science [7].…”

Evaluation of Neutron Nuclear Data on Bromine and Krypton Isotopes for JENDL-4.0

“…29 at an incident neutron energy of 14.63 MeV. As in the case 45) of 75 As, we assumed a pseudoresonance at an excitation energy of 2.0 MeV for 79;81 Br, which can substitute for the missing collective enhancement phenomenologically. The cross section for the resonance was calculated by DWBA using the neutron potential parameters mentioned in Sec.…”