Evidence for incomplete fusion on the 12C+208Pb and 13C+207Pb reactions in above-barrier energies

The complete, incomplete and fission cross sections are being measured for C-12,C-13 + Pb-208,Pb-207 systems to investigate the influence of breakup at above-barrier energies which form the same compound nucleus at the same excitation energies. The alpha-active heavy reaction products are measured for most dominant reaction xn-channels along with fission cross sections which originate almost exclusively from the complete fusion (CF). The results from the present systems show substantial components from the incomplete fusion in addition to CF. The CF cross section is suppressed by 12 +/- 2% for C-12 and 3 +/- 2% for 13C compared with the single-barrier penetration model calculations. A systematic variation of the suppression of CF for reactions of weakly bound nuclei Li-6,Li-7, Be-9, B-10,B-11 and C-12,C-13 on targets of Pb-207,Pb-208 and Bi-209 is being found as a function of the breakup threshold energy.