At 200, 300, and 400 MeV bombarding energies, we measured cross section angular distributions for the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$(p,n${)}^7$Be(g.s.+0.43 MeV) reaction and 0° cross sections for the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$(p,n${)}^{12}$N(g.s.) reaction. Systematics of these reactions are presented. The center-of-mass cross section for the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}$(p,n${)}^7$Be(g.s.+0.43 MeV) reaction, when plotted as a function of momentum transfer, is nearly independent of energy. The laboratory cross section for this reaction at 0° in the energy range from 60 to 400 MeV is also independent of energy, having a constant value, to within experimental errors, of 35.5 mb/sr with an estimated uncertainty of ±1.5 mb/sr.

• Received 13 March 1989

DOI:https://doi.org/10.1103/PhysRevC.40.22