REACTION-MECHANISM COEXISTENCE IN THE 123 MEV F-19-56 REACTION(FE)

Mass and charge identified ejectiles, spanning from B-11 to Ne-22, hav e been detected in the 123 MeV F-19+ Fe-56 reaction. The coexistence o f deep inelastic collision (DIC) and incomplete fusion (IF) mechanisms has been observed. The shape of the energy spectra and their behavior with angle allowed us to identify two components: The less dissipativ e one was dominating near the grazing angle. For both components exper imental optimum Q values were derived. Two approaches based on the sum rule (SR) model of Wilczynski were used to calculate DIC and IF contr ibutions to the complex fragment cross sections. Both prescriptions fi t reasonably well experimental ejectile cross sections and Q optimum v alues. Results of the present investigation support the idea that the DIC can be treated on, the same footing as IF in the SR model once the first process is confined in an inner angular momentum window, starti ng from the maximum fusion angular momentum, with respect to quasielas tic processes.