Abstract
The reaction ${\mathrm{Mg}}^{24}(\ensuremath{\alpha},{\mathrm{Be}}^{7}){\mathrm{Ne}}^{21}$ is investigated with alpha particles in the energy range 35-63 MeV. The measured cross sections are compared with the cross sections for ${\mathrm{Al}}^{27}(p,{\mathrm{Be}}^{7}){\mathrm{Ne}}^{21}$, a reaction which proceeds through the same compound nucleus, ${\mathrm{Si}}^{28}$. At fixed excitation energy of the compound nucleus (C.N.), the alpha-induced reaction has a higher cross section for ${E}_{\mathrm{C}.\mathrm{N}.}>40$ MeV. The cross-section ratio $\frac{\ensuremath{\sigma}(\ensuremath{\alpha})}{\ensuremath{\sigma}(p)}$ increases from 4.4\ifmmode\pm\else\textpm\fi{}1.0 at ${E}_{\mathrm{C}.\mathrm{N}.}=50$ MeV to 6.3\ifmmode\pm\else\textpm\fi{}1.4 at ${E}_{\mathrm{C}.\mathrm{N}.}=60$ MeV. Part of this significant difference is shown to be due to angular-momentum effects in compound-nuclear processes. The balance is attributed to the multinucleon pickup by the He ion. A similar effect is observed in the reactions ${\mathrm{Al}}^{27}(p,\ensuremath{\alpha}pn)$ and ${\mathrm{Mg}}^{24}(\ensuremath{\alpha},\ensuremath{\alpha}pn)$.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call