Reaction dynamics at the barrier for heavy compound systems

To investigate basic properties of the fusion reaction dynamics for heavy compound systems the partial wave distribution δl; extracted from measured γ multiplicities can be employed as an alternative to the classically used fusion/fission excitation functions. A variety of reactions leading to compound nuclei (CN) in the Pb region can be used to investigate features like the fusion-fission competition, the role of deformation in the fusion of heavy systems and a possible effect of the Z = 8 shell on the enhancement of evaporation residue (ER) production. The measured spin distribution (SD) can provide information on the single partial wave cross sections which is hidden in the integral fusion cross section. We started a series of experiments to measure those properties for the reactions at the Laboratori Nazionali di Legnaro, Italy. In order to extract the CN spin distribution, γ multiplicities are measured by using the γ-detector array GASP and its inner ball in the multiplicity filter mode. (author)