A new empirical formula for 14–15 MeV neutron-induced (n, p) reaction cross sections

Abstract

In this study, pre-equilibrium neutron-emission spectra produced by (n,xn) reactions on nuclei 232 Th and 238 U have been calculated. Angle-integrated cross sections in neutron induced reactions on targets 232 Th and 238 U have been calculated at the bombarding energies up to 18 MeV. We have investigated multiple pre-equilibrium matrix element constant from internal transition for 232 Th (n,xn) neutron emission spectra. In the calculations, the geometry dependent hybrid model and the cascade exciton model including the effects of pre-equilibrium have been used. In addition, we have described how multiple pre-equilibrium emissions can be included in the Feshbach-Kerman-Koonin (FKK) fully quantum-mechanical theory. By analyzing (n,xn) reaction on 232 Th and 238 U, with the incident energy from 2 MeV to 18 MeV, the importance of multiple pre-equilibrium emission can be seen clearly. All calculated results have been compared with experimental data. The obtained results have been discussed and compared with the available experimental data and found agreement with each other. 541

The Comparison of (n,p), (n,α), (n,2n) and (α,n) Reaction Cross-Sections for 7Li and 9Be Target Nuclei

“…The systematic (n,p), (n,a), and (n,2n) formulas proposed by different authors are given in Tables 1, 2, and 3, respectively. Some of their names are Levkovskii [4], Broeders and Konobeyev [10], Tel et al [28,29], Bychkov et al [30], Kumabe and Fukuda [31], Konno et al…”

“…Habbani and Osman [35] proposed systematic based on the statistical model including odd-even effect for (n,p), (n,a), and (n,2n) reaction cross-sections for 14.5 MeV neutrons. Tel et al [28] obtained a new empirical (n,p) cross-section formula taking shell model and pairing effects into account. Broeders and Konobeyev [10] proposed a semi-empirical formula with contribution of both non-equilibrium and equilibrium proton emissions for (n,p) reaction cross-section at 14.5, 20, and 30 MeV neutron energies.…”

“…1 and 3, the interaction reaction cross section for projectile nucleus as neutron (or proton) for 7 Li and 9 Be target nuclei are calculated to be 382 and 428 mb, respectively. The (n,p) reaction cross-section systematics at 14-15 MeV incident energy belonging to Levkovskii [4], Broeders and Konobeyev [10], Tel et al [28,29], Kumabe and Fukuda [31], and Konno et al…”

Semi-Empirical Formula with New Coefficients of the (α,n) Reaction Cross-Section

“…Habbani and Osman proposed systematics for (n,p), (n,α), and (n,np) reaction cross-section for 14.5 MeV neutrons and the obtained formula was based on the statistical model with the Q-value and odd-even effect [6]. Tel et al obtained a new empirical (n,p) cross-section formula tak-B-129 ing shell model and pairing effect into consideration by modifying Levkovskii's empirical formula [7]. Broeders and Konobeyev proposed semi-empirical formula of (n,p) reaction cross-section at 14.5, 20, 30 MeV neutron energies.…”

“…A great number of empirical and semi-empirical crosssection formulae have been proposed for different target nuclei irradiated with uncharged neutron and charged particle at the specific energies [1][2][3][4][5][6][7][8][9][10][11][12]; however, there is not any study on cross-section systematics of alphainduced reactions. As a result of alpha-induced reactions, in particular the production of significant medical radioisotopes used in nuclear medicine occurs [13][14][15].…”