Empirical formulas for 14-MeV (n,p) and (n,.ALPHA.) cross sections.

Abstract

Empirical formulas for the 14 MeV (n,p) and (n, a) cross sections given by Levkovskii were modified separately in three ranges of mass number, in each of which, coefficients modifying Levkovskii's formulas were determined by least-squares fitting to experimental cross sections. The resulting modified formulas yielded cross sections representing markedly smaller chi-square deviations from experimental values, and moreover gathered closer to unity, compared with calculation using Levkovskii's original formulas.

New calculations of cyclotron production cross sections of some positron emitting radioisotopes in proton induced reactions

“…If the Q-value decreases smoothly with increasing mass number for a given element, the cross sections also decrease smoothly. The actual experimental (n,p) and (n,α) cross sections decrease smoothly with increasing mass number for a given element [57], despite the large differences in true Q-value between magic and non-magic nuclei, and between even-Z-even-N and odd nuclei. This behavior can be explained in terms of Q-value.…”

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

“…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. Many studies on (n,p), (n,a) and (n,2n) reaction cross-section formulas for 14-15 MeV neutrons have been made by the authors [7,[30][31][32][33][34][35][36][37]. These formulas are given for (n,p), (n,a) and (n,2n) reactions in Tables 1, 2 and 3, respectively.…”

“…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…”

“…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

“…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].…”