Effects of sequential decay in nuclear element distributions of complex fragments for 86Kr + 27Al at 10.6 MeV/u

Abstract

In order to study the reaction mechanisms of Intermediate Mass Fragments (IMF) as well as Fission Products (FP) from hot nuclei, we have performed the experiment using the RIKEN Ring Cyclotron for 84Kr + 27Al at 10.6 MeV/u in which the complete fusion is still dominant. The experimental nuclear element Z distributions of IMF and FP are analyzed extensively by using the Extended Hanser Feshbach Method (EHFM) and it is concluded the sequential decayis playing an important role and the fully equilibrated compound states of 111In at 200 MeV do exist with the angular momentum state of 86 ℏ above the limit of rotating liquid drop model of 68 ℏ. A large apparent difference observed in the previous experimental Z-distributions for 84Kr + 27Al at 5.9 MeV/u and 3He + Ag at 30 MeV/u, which form nearly the same compound nucleus In at ≅ 100 MeV, is interpreted consistently in terms of the EHFM, showing that IMF and FP decay from the different angular momentum windows and a first chance decay is just enough for reproducing the data.