Obtaining a new empirical (n,2n) cross section formula using Flerov and Talyzin non-elastic cross sections at 14-15 MeV.

The knowledge of (n,2n) cross sections is required in shielding and breeding calculations. It's also important, in nuclear reactor applications, for neutron dosimetry research. In nuclear reaction mechanism, (n,2n) reaction channel is the dominant reaction for medium and heavy mass nuclei at 14 MeV energy range. The empirical and semi-empirical (n,2n) reaction cross sections have been investigated by many authors, but theoretical calculations have not been adequate because of the character of the nuclear structure is not exactly known. In this work, a new empirical formula has been proposed to calculate the (n,2n) reaction cross sections at 14-15 MeV neutron incident energy. In the calculations different fitting method have been used to obtain cross-section formula for target nuclei in the range 14 ≤ A ≤ 241 mass number. The (n,2n) experimental cross sections have been taken from EXFOR nuclear data library. In this new formula, the Flerov and Talyzin expression for the inelastic cross section σne was used to fit the experimental (n,2n) cross sections. It has been observed that the obtained formulas give quite coherent results with the experimental data.

Simple parametrization of (n,d) cross sections using Flerov and Talyzin's formula.

This article aims at providing new cross section data from empirical formulas for the (n,d) reactions of which experimental measurements at 14-15 MeV energy are not available or limited. If the experimental data for a nuclear reaction at a given energy are scarce, theoretical calculations and also developing empirical formulas have a critical importance. Here, we propose a new empirical formula of (n,d) reactions for analysis of the relationship between the experimental data and the parameters of empirical formula. The present formula was obtained by using the non-elastic Flerov and Talyzin expression to calculate (n,d) cross sections at 14-15 MeV. Due to the good overall agreement with the measured cross sections, our empirical formula with polynomial fitting model including asymmetry parameter can be useful in planning new experiments of (n,d) reactions for energies around 14 MeV.

Investigation of (γ, p) reaction cross-section calculations of 40Ca, 70Ge and 90Zr isotopes.

Calcium, Germanium and Zirconium isotopes can be used in semiconductors, fuel rods and as cooling materials in nuclear reactor technology. During the various occurred reactions in reactors, gas production via gamma reactions or temperature rise can severely damage the reactor materials. Therefore, it is necessary to know the effects of particles interacting with nuclear reactor materials in such cases. In this study, (γ,p) cross-sections have been calculated for 40Ca, 70Ge and 90Zr nuclei using different level density models.TALYS 1.9 and EMPIRE 3.2.3 codes have been used for level density models calculations for photon energies up to 40 MeV. Then, for these nuclei, theoretical (γ,p) cross-section calculation have been performed by using newly developed asymmetry dependent Tel et al. (2018) (γ,p) formula. Lastly, these theoretical calculations have been compared with experimental EXFOR data.