Cross sections for the production of ${}_{}{}^7{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$, and ${}_{}{}^{28}{}_{}{}^{}\mathrm{Mg}$ from Mg, Al, and ${\mathrm{SiO}}_2$ by protons in the 80 to 800 MeV energy range have been determined by direct foil $\gamma$-ray spectrometry. These nuclides are of interest in several fields of astrophysics, cosmochemistry, and nuclear science. The values obtained are compared with other experimental values and with values predicted using empirical formulas and Monte Carlo methods. A mathematical form for the $\mathrm{Al}\mathrm{}(p,X)\mathrm{}{}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$ excitation function above 100 MeV is proposed.

NUCLEAR REACTIONS Natural Mg, Al, $\mathrm{Si}{\mathrm{O}}_2\mathrm{}(p,X)\mathrm{}{}_{}{}^7{}_{}{}^{}\mathrm{Be}$, ${}_{}{}^{22}{}_{}{}^{}\mathrm{Na}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Mg}$, $E=82-800\mathrm{}$ MeV; measured $\sigma \mathrm{}\left(E\right)\mathrm{}$.

• Received 12 May 1976

DOI:https://doi.org/10.1103/PhysRevC.14.1506