Excitation of Giant-resonances In Intermediate Energy Heavy-ion Reactions

Quasielastic and deep inelastic processes in the reaction 16O + 208Pb have been studied at bombarding energies of 10–80 MeV per nucleon. The excitation probability of the giant modes becomes larger with increasing energies. At a given bombarding energy the multiple excitation of low-lying modes becomes predominant as the angle of observation moves away from the grazing angle. Near grazing, no appreciable background of this character is found for bombarding energies above 30 MeV per nucleon. At these energies the electromagnetic interaction becomes the most effective way to excite the giant modes in the excitation energy interval of 10–20 MeV. The importance of Coulomb excitation for the highest bombarding energies makes the excitation of isovector modes no longer negligible. © 1980, All rights reserved.