Absolute cross sections for the ($p,n$) reactions on ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$, ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}$, and ${}_{}{}^{107}{}_{}{}^{}\mathrm{Ag}$ at proton energies from 2.5 to 25 MeV were determined by the activation method. Metal foil targets of natural isotopic abundance were used; therefore, the results for ${}_{}{}^{63}{}_{}{}^{}\mathrm{Zn}$ above 22.3 MeV and for ${}_{}{}^{107}{}_{}{}^{}\mathrm{Cd}$ above 18.8 MeV include contributions from ($p,3n$) reactions. Beam intensities were measured with a Faraday cup. Disintegration rates of the product nuclei were determined by assaying their $\gamma$ rays with calibrated Ge(Li) detector systems. Comparisons of the present cross sections are made with a complete compilation of previous measurements and with calculations based on a Monte Carlo intranuclear-cascade-statistical-evaporation model. Half-lives for ${}_{}{}^{63}{}_{}{}^{}\mathrm{Zn}$ and ${}_{}{}^{107}{}_{}{}^{}\mathrm{Cd}$ were determined to be 38.0 ± 0.1 min and 6.50 ± 0.02 h, respectively.

[NUCLEAR REACTIONS ${}_{}{}^{63,65}{}_{}{}^{}\mathrm{Cu}$, ${}_{}{}^{107}{}_{}{}^{}\mathrm{Ag}(p,n)$, $E=2.5-25\mathrm{}$ MeV; measured $\sigma \mathrm{}\left(E\right)\mathrm{}$. Natural targets, Faraday cup, Ge(Li) detector. RADIOACTIVITY ${}_{}{}^{63}{}_{}{}^{}\mathrm{Zn}$, ${}_{}{}^{107}{}_{}{}^{}\mathrm{Cd}$; measured $T_{\frac{1}{2}}$.]

• Received 3 December 1973

DOI:https://doi.org/10.1103/PhysRevC.9.1819