Characteristcs of binary scission configurations in proton-induced fissionof actinides

Two kinds of scission configurations for certain mass division have been ve rified by the accurate measurements of fragment velocities in proton-induce d fission of actinides: compact and elongated scission configurations. A co rrelation between the binary scission configurations and mass yield distrib utions reveals that elongated scission configurations are associated with t he symmetric mass distribution and compact scission configurations with the asymmetric mass distribution. The elongation properties of nuclei at sciss ion in a wide range of actinides fissions are studied. The results suggest that the compact and the elongated scission configurations in light actinid es fission smoothly change to the scission properties of the symmetric and the asymmetic modes in heavy actinides fission.