Production cross sections for ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$ and ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$ have been measured by direct $\gamma$ counting of targets of Si, Mg, Fe, and Ni irradiated by protons of 1, 2, 3, and 23 GeV. In essentially all cases significant differences are found with previously reported values. The results are also compared with a recent semiempirical formula.

NUCLEAR REACTIONS Mg, Si, Fe, $\mathrm{Ni}(p, x)$ ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$, $E=1, 2, 3, 23$ GeV measured $\sigma \text{'}\mathrm{s}$. Ge(Li) detector.

• Received 28 April 1975

DOI:https://doi.org/10.1103/PhysRevC.12.915