Decay studies for states in 9 Be up to 11 MeV: Insights into the n + 8 Be and α + 5 He cluster stucture

An experiment was performed to study the $^{9}\mathrm{Be}$($^{6}\mathrm{Li}$,$^{6}\mathrm{Li}$)$^{9}\mathrm{Be}$${}^{*}$ $\ensuremath{\rightarrow}\ensuremath{\alpha}+\ensuremath{\alpha}+n$ reaction. This experiment was designed to study the breakup of $^{9}\mathrm{Be}$ in an attempt to quantify the breakup yield for each of the decay channels ($n+$ $^{8}\mathrm{Be}$ ${}^{\mathrm{g}.\mathrm{s}},n+$ $^{8}\mathrm{Be}$ ${}^{{2}^{+}}$, and $\ensuremath{\alpha}+$ $^{5}\mathrm{He}$ ${}^{\mathrm{g}.\mathrm{s}}$) from the low-lying states. The results suggest that the population of states in $^{9}\mathrm{Be}$ from 1.68 to 11.28 MeV can be identified. Branching ratios for each of the breakup channels have been estimated for these states. These results are compared with earlier experiments and with theoretical predictions. They confirm the theoretical claim that the $n+$ $^{8}\mathrm{Be}$ ${}^{{2}^{+}}$ and $\ensuremath{\alpha}+$ $^{5}\mathrm{He}$ ${}^{\mathrm{g}.\mathrm{s}}$ channels increase in importance at higher excitation energies.