Suppression of complete fusion due to breakup in the reactions $^{10,11}$B + $^{209}$Bi

Above-barrier cross sections of fission and {alpha}-active heavy reaction products were measured for the reactions of {sup 10,11}B with {sup 209}Bi. Systematic analysis showed that the fission originates almost exclusively from complete fusion (CF). Existing measurements of above-barrier fusion products for the {sup 30}Si+{sup 186}W 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 {sup 10,11}B+{sup 209}Bi 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 {sup 10}B and 7% for {sup 11}B. A consistent and systematic variation of the suppression of CF for reactions of the weakly bound nuclei {sup 6,7}Li, {sup 9}Be, and {sup 10,11}B on targets of {sup 208}Pb and {sup 209}Bi is found as a function of the breakup threshold energy.