The ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}(\alpha , \mathrm{n}){}_{}{}^{51}{}_{}{}^{}\mathrm{Cr}$ and ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}(\alpha , \mathrm{n}){}_{}{}^{54}{}_{}{}^{}\mathrm{Mn}$ cross sections were measured in the energy range 6-13 MeV to an accuracy of about 3%. The activation method was used for the determination of the reaction yields, and the product of incident flux and target thickness was determined from measurements of Rutherford scattering. Using known information on the competing charged-particle emission and extensive statistical model calculations, the total reaction cross sections for $\alpha$ particles on ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}$ and ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}$ could be derived with similar accuracy. Especially at lower energies our results are considerably smaller than the predictions of the widely-used Huizenga-Igo optical potential and support the potential of McFadden and Satchler.

NUCLEAR REACTIONS ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}(\alpha , \mathrm{n})$, $E_{\alpha }=6\mathrm{} \mathrm{to} 13$ MeV; ${}_{}{}^{51}{}_{}{}^{}\mathrm{V}(\alpha , \mathrm{n})$, $E_{\alpha }=6.5\mathrm{} \mathrm{to} 12$ MeV; measured yield of residual nuclides; deduced total $\alpha$-reaction cross sections. Comparison with optical model calculations.

• Received 1 June 1983

DOI:https://doi.org/10.1103/PhysRevC.28.2278