At energies well above the Coulomb barrier, the slope of the angular distributions of excitation-energy bins extracted from the spectra of most outgoing products observed in ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$-induced reactions is found to be a smooth function of the measured $Q$ value. A friction model is proposed which closely reproduces this dependence.

NUCLEAR REACTIONS $X({}_{}{}^{16}{}_{}{}^{}\mathrm{O},Y)$, $X={}_{}{}^{12}{}_{}{}^{}\mathrm{C},{}_{}{}^{27}{}_{}{}^{}\mathrm{Al},{}_{}{}^{60}{}_{}{}^{}\mathrm{Ni},{}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$, $Y=\mathrm{projectilelike}\mathrm{fragments}$ ($Z=3-9\mathrm{}$), $E=100-315\mathrm{}$ MeV. Correlation between slopes of $\sigma (E,Z,\theta )$ and energy-loss found. Friction model proposed. Deduced frictional coefficients, interaction times.

• Received 26 May 1981

DOI:https://doi.org/10.1103/PhysRevC.24.2777