Decay mechanism of a highly excited nucleus produced in the reaction Kr-84+Al-27 at 10.6 MeV/nucleon

Abstract The cross section, energy distribution and angular distribution of complex fragments emitted in the reaction 84 Kr + 27 Al at the incident energy of 10.6 MeV/nucleon were measured to study the decay mechanism of a highly excited nucleus. Through coincidence measurements between the light charged particles and the binary decay fragments it is found that the pre-scission charge multiplicity is about 80% of the total one. The experimental distributions are well reproduced by the Extended Hauser-Feshbach Method (EHFM), introducing a cut-off energy of the excitation energy of fragments E cut-off . The fission delay time is determined to be 2 × 10 −20 seconds. The role and the physical meaning of E cut-off is discussed.