Heavy residues and intermediate-mass fragment production in dissipative Au-197+Kr-86 collisions at E/A=35 MeV - art. no. 034603

Neutrons and charged light and intermediate-mass products from the Au-197 Kr-86 reaction at E-lab/A = 35 MeV were measured with 4 pi angular coverag e, in coincidence with projectilelike (PLFs) and targetlike fragments (TLFs ). The characteristics of PLF and TLF yields and their correlation with neu tron, light-charged particles. and intermediate-mass fragments (IMFs) are c onsistent with a scenario where essentially all collisions proceed through a dissipative stage. It is found that the damping of the available kinetic energy into thermal excitation is essentially incomplete, with no positive evidence for complete damping. Slow, massive reaction products are observed with significant yields. These products, termed also heavy residues, are i dentified as TLF evaporation residues and as TLF fission fragments. The TLF fission mode is seen to fade away in favor of TLF evaporation residue prod uction for excitation energies above 3-4 MeV/nucleon. The suppression of th e TLF fission can be traced to the dynamical IMF production process which r educes considerably the sizes of the primary reaction fragments and, hence. their fissility.