Backward angle cross sections for ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$+${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ reaction products

Reactions induced by bombarding a ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ gas target with ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$ ions were studied. Evaporation residues as well as target-like recoils were measured over a wide range of $Q$ values. The yield of particles with 6 ≤ Z ≤ 9 was found to be forward peaked in the laboratory frame. These target-like particles emerge with center-of-mass kinetic energies that, on the average, are independent of the reaction angle. Their combined cross section has a $\frac{1}{{sin\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}}$ angular dependence. If this cross section is assumed to be symmetric about 90° (c.m.) the integrated cross section is about 10% of the measured evaporation residue cross section at a center-of-mass energy of 54 MeV.

NUCLEAR REACTIONS ${}_{}{}^{27}{}_{}{}^{}\mathrm{Al}$+${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, $E_{{}_{}{}^{27}{}_{}{}^{}\mathrm{Al}}=105, 145$ MeV; measured $\frac{d\sigma }{d\Omega }$ for reaction products with $6<~Z<~9$ and $Z>\mathrm{}13\mathrm{}$ for $2.5°<~{\theta }_L<~15°$. Extracted $\sigma$ for evaporation residues and damped events.