He-Ion Induced Reactions of Aluminum and Magnesium

The ${\mathrm{Al}}^{27}(\alpha , 3p){\mathrm{Mg}}^{28}$ and ${\mathrm{Mg}}^{26}(\alpha , 2p){\mathrm{Mg}}^{28}$ reactions produced by the bombardment of aluminum and magnesium targets with 42-Mev He ions have been studied. The excitation functions for these reactions are presented. At 40-Mev He-ion bombarding energy, the cross section for the ($\alpha , 3p$) is about 80 microbarns and the peak yield of the ($\alpha , 2p$) reaction observed at 34 Mev is 1.65 mb. Excitation functions are also given for the production of ${\mathrm{Na}}^{22}$ from the bombardment of aluminum with 30-42 Mev He ions, which proceeds chiefly through the reaction ${\mathrm{Al}}^{27}(\alpha , 2\alpha n){\mathrm{Na}}^{22}$, and of ${\mathrm{Na}}^{24}$ from the bombardment of natural magnesium, primarily through the ${\mathrm{Mg}}^{25}(\alpha , \alpha p){\mathrm{Na}}^{24}$ reaction.