Suppression of complete fusion due to breakup in the reactions B10,11+Bi209

Above-barrier cross sections of fission and α-active heavy reaction products were measured for the reactions of B10,11 with Bi209. Systematic analysis showed that the fission originates almost exclusively from complete fusion (CF). Existing measurements of above-barrier fusion products for the Si30+W186 reaction, assumed to proceed exclusively through CF, were extrapolated to the current systems using statistical model calculations. This extrapolation showed that the heavy reaction products from the B10,11+Bi209 reactions include substantial components from incomplete fusion as well as from CF. Compared with fusion calculations without breakup, the CF cross sections are suppressed by 15% for B10 and 7% for B11. A consistent and systematic variation of the suppression of CF for reactions of the weakly bound nuclei Li6,7, Be9, and B10,11 on targets of Pb208 and Bi209 is found as a function of the breakup threshold energy.