Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2017, Vol. 28 ›› Issue (10): 147 doi: 10.1007/s41365-017-0298-4


Response of multistep compound pre-equilibrium reaction cross-sections for the (p, n) reactions to forms of optical model parameters

Felix S. Olise 1 , Oludaisi I. Oladunjoye 1 , Afis Ajala 1 , Sunday D. Olorunfunmi , Hezekiah B. Olaniyi 1   

  1. 1 Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife 220005, Nigeria
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Felix S. Olise, Oludaisi I. Oladunjoye, Afis Ajala, Sunday D. Olorunfunmi, Hezekiah B. Olaniyi. Response of multistep compound pre-equilibrium reaction cross-sections for the (p, n) reactions to forms of optical model parameters.Nuclear Science and Techniques, 2017, 28(10): 147     doi: 10.1007/s41365-017-0298-4


In furtherance to improving agreement between calculated and experimental nuclear data, the nuclear reaction code GAMME was used to calculate the multistep compound (MSC) nucleus double differential cross sections (DDCs) for proton-induced neutron emission reactions using the Feshbach-Kerman-Koonin (FKK) formalism. The cross sections were obtained for reactor structural materials involving 52Cr(p, n)52Mn, 56Fe(p, n)56Co, and 60Ni(p, n)60Cu reactions at 22.2 MeV incident energy using the zero-range reaction mechanism. Effective residual interaction strength was 28 MeV, and different optical potential parameters were used for the entrance and exit channels of the proton-neutron interactions. The calculated DDCs were fitted to experimental data at the same backward angle of 150°, where the MSC processes dominate. The calculated and experimental data agree well in the region of pre-equilibrium (MSC) reaction dominance against a weaker fit at the lower emission energies. We attribute underestimations to contributions from the other reaction channels and disagreement at higher outgoing energies to reactions to collectively excited states. Contrary to the FKK multi-step direct calculations, contributions from the higher stages to the DDCs are significant. Different sets of parameters resulted in varying levels of agreement of calculated and experimental data for the considered nuclei.

Key words: Proton-neutron interaction, Multi-step compound theory, Optical model parameters, Structural materials, Nuclear reactor facilities