Suppression of fusion by breakup: Resolving the discrepancy between the reactions of 9Be with 208Pb and 209Bi

Complete fusion cross sections for Be-9 incident on Pb-208 and Bi-209 have been measured at energies greater than the fusion barrier to investigate the large differences in their reported complete fusion cross sections. Relative xn and fission cross sections are in good agreement. Thus, it is concluded that the differences arise from errors in absolute normalization in the previous measurements. The present measurements show that the above-barrier complete fusion cross sections for the reactions of Be-9 with Bi-209 and Pb-208 are very similar, which resolves the previously observed anomaly. Complete fusion for the reaction of Be-9 with Bi-209 is found to be suppressed by similar to 32% compared to the expectations of a single-barrier penetration model, which is in close agreement with the value previously determined for the reaction with Pb-208.