New Total-Cross-Section Measurements for the ReactionsN14(N14,N13)N15andB10(N14,N13)B11

Abstract

Thick targets of AgCN and ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ were bombarded with ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ ions accelerated in the Oak Ridge Tandem Van de Graaff. The amount of ${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$ present in each irradiated sample was determined by the detection of the 10-min positron activity characteristic of the isotope. In this manner cross sections were measured for the neutron-transfer reactions ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$(${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$,${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$)${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ and ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$(${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$,${}_{}{}^{13}{}_{}{}^{}\mathrm{N}$)${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$. The (assumed equal) neutron reduced widths in ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ and ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$ were determined by applying the tunneling theory to the ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$-on-${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ measurements. The reduced width in ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ was then calculated from the cross-section data for the reaction of ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ on ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ by the use of the now measured reduced width in ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$. The ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ and ${}_{}{}^{11}{}_{}{}^{}\mathrm{B}$ reduced widths were found to agree with the same values as determined from the bound-state, single-particle, radial wave functions that have been calculated by using a Woods-Saxon potential. In resolving the experimental decay curves, 2- and 20-min components were found for the ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$ and ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$ targets, respectively. These activities were ascribed to the ${}_{}{}^{15}{}_{}{}^{}\mathrm{O}$ and ${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ which result from the proton-transfer reactions ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$(${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$,${}_{}{}^{15}{}_{}{}^{}\mathrm{O}$)${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{10}{}_{}{}^{}\mathrm{B}$(${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$,${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$)${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$; cross sections for these reactions were also measured.