Angular correlations have been investigated between projectilelike fragments (from Li to O) and α particles in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$+${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$ collisions at 87.4 MeV. For C-$\alpha$ and O-$\alpha$ correlations, clear evidence of the sequential $\alpha$ decays of projectilelike fragments was observed at forward angles. In ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}({}_{}{}^{16}{}_{}{}^{}\mathrm{O}, {}_{}{}^{12}{}_{}{}^{}\mathrm{C}(\mathrm{g}.\mathrm{s}.\mathrm{}\left)\alpha \right){}_{}{}^{27}{}_{}{}^{}\mathrm{Al}(\mathrm{g}.\mathrm{s}.\mathrm{})$, the reaction proceeds mainly via the sequential $\alpha$ decay of the excited ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ nucleus at $E_{\alpha }\cong 10, 11.6, 13.2, 15.2, 16.2, \mathrm{and} 21$ MeV. For the O-$\alpha$ case, evidence of the sequential α decay of ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$* ($E_x\cong 8.7, 12.0, \mathrm{and} 15.2$ MeV) was observed.

NUCLEAR REACTIONS ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$+${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$, $E_{\mathrm{lab}}=87.4\mathrm{}$ MeV; measured $\frac{d^2\sigma }{d{\Omega }_{\mathrm{HI}}d{\Omega }_{\alpha }}$, coincidence between O, N, C, B, Li, and $\alpha$, in-plane and out-of-plane angular correlations, ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$ target.

• Received 27 May 1982

DOI:https://doi.org/10.1103/PhysRevC.27.2630