Influence of multiple excitation of low lying states and giant resonances on heavy ion inelastic spectra

The inelastic excitation probabilities of ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$ impinged upon by ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ projectiles at bombarding energies between 10 and 100 MeV/nucleon are calculated in a model in which the excitation amplitudes are evaluated along classical trajectories. The excited states are calculated in the random-phase approximation and the nuclear and Coulomb excitations of both low lying states and giant resonances of the target and projectile are taken into account. A general feature of the calculated spectra for near-grazing impact parameters and bombarding energies above 20 MeV/nucleon is the presence of broad regularly spaced structures mainly due to the excitation of multiphonon states built with 2ħω giant resonances. Cross-section estimates for the inelastic excitations are given.