Dynamical production of intermediate-mass fragments in peripheral 209Bi+136Xe collisions at

Intermediate-mass fragments (IMF) from the reaction 209Bi+136Xe at ElabA=28 MeV have been measured in coincidence with other charged reaction products, as well as with neutrons. The IMF emission patterns are seen to exhibit signatures of two mechanisms — statistical emission from the fully accelerated massive reaction partners and a fast dynamical emission from a single effective source. The latter mechanism, possibly involving a multiple neck rupture, becomes dominating for least dissipative collisions characterized by low associated light particle multiplicities.