Transfer reactions and sequential decays of the projectile-like fragments in the 60 MeV/nucleon 40Ar + natAg, 197Au Reactions

Abstract

Light charged particles and nuclei (1⩽Z⩽8) have been detected in a large forward plastic multidetector (3° < θ <30°) in coincidence with projectile-like fragments (5⩽Z⩽ 19) in the 40Ar+ natAg and 40Ar + 197Au reactions at 60 MeV/nucleon bombarding energy. It is shown that transfer reactions from the projectile to the target are still present at such a high incident energy. Most of the coincident Z = 2 particles are found to be sequentially emitted by excited primary projectile-like fragments. The sequential decay pattern is also observed with the Z = 1 particles, but the main part of those particles probably arise from other mechanisms such as direct and/or pre-equilibrium emission. An attempt is made to derive the excitation energies of the primary projectile-like fragments from these coincident events. The data are not reproduced by the usual models such as the high-energy-abrasion model, the equal-temperature-limit assumption or the equal partition of the excitation energy.