Fusion and nonfusion processes in reactions induced by 10-100-MeVLi6ions with Fe targets

Excitation functions and projected recoil ranges for radioactive nuclei produced in the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ bombardment of ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$ an ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$ targets over 10 to 100 MeV energy range have been measured using the activation technique. At 55 and 85 MeV differential ranges have also been measured for the ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$ target. Using the in-beam gamma-ray technique production cross sections for many residual nuclei were measured for the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ + ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$ system for a ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ energy range of 55 to 99 MeV. Close to 90% of the optical model reaction cross section is observed over the entire energy range. About 80% of the observed cross section corresponds to statistical evaporation of the compound nucleus. Above about 30 MeV ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ energy ${}_{}{}^{56}{}_{}{}^{}\mathrm{Fe}$(${}_{}{}^6{}_{}{}^{}\mathrm{Li}$,$\alpha$)${}_{}{}^{58}{}_{}{}^{}\mathrm{Co}$ transfer process can explain the observed behavior of recoil ranges. It contributes about 300 mb to the production of various nuclei reached through evaporation decay of ${}_{}{}^{58}{}_{}{}^{}\mathrm{Co}$. Pre-equilibrium nucleon emission appears to be noticeable above 60 MeV and contributes 100 mb to the production process at 80 MeV. A reasonable account of the observed cross section for various product nuclei is given by the predictions of the fusion-evaporation model. In its fusion characteristics the ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ projectile appears to behave very much like other light heavy ions.