Cross Section and Angular Distribution of Products in "Quasifission" Reactions Induced by 525-MeVKr84Ions on aBi209Target

We observed "quasifission" events (or "incomplete fusion" events) in the bombardment of ${}_{}{}^{209}{}_{}{}^{}\mathrm{Bi}$ by 525-MeV ${}_{}{}^{84}{}_{}{}^{}\mathrm{Kr}$ ions. By a simple method, the angular distribution of these events has been obtained. Its maximum value appears around 65° lab, i.e., ∼95° c.m. The integrated cross section for this reaction is 500 mb, more than $\frac{1}{2}$ of the total reaction cross section. No symmetric fission coming from a complete fusion nucleus has been observed, and it seems that the "quasifission" reaction occurs instead of complete fusion, as was previously observed at 500 MeV bombarding energy.