Photo-neutron Cross Section Calculations of Several Structural Fusion Materials

Abstract

In this study, the theoretical photo-neutron cross-sections produced by (gamma,n) reactions for several structural fusion materials such as V-51, Mn-55, Ni-58, Zr-90,Zr-91,Zr-92,Zr-94, and Ta-181 have been investigated in the incident energy range of 7-40 MeV. Reaction cross-sections as a function of photon energy have been calculated theoretically using the PCROSS and TALYS 1.2 computer codes. TALYS 1.2 default and pre-equilibrium models have been used to calculate the pre-equilibrium photo-neutron cross-sections. For the reaction equilibrium component, PCROSS Weisskopf-Ewing model calculations have been preferred. The calculated results have been compared with each other and against the experimental data in the existing databases EXFOR and TENDL-2011. PCROSS Weisskopf-Ewing model calculations show a similar structure with experimental data but they are higher than the experimental values for all reactions except for Zr-90(gamma,n)Zr-89 reaction. Generally, TALYS 1.2 default and pre-equilibrium model cross-section calculations are the best agreement with the experimental data for all reactions except for Ni-58(gamma,n)Ni-57 reaction along the incident photon energy in this study. The TALYS 1.2 curves fit the TENDL-2011 data the best. If photo-neutron cross-section data is needed for an isotope where there is no experimental data available for comparison, TALYS 1.2 pre-equilibrium option has been recommended.