DECAY MECHANISM OF A HIGHLY EXCITED NUCLEUS PRODUCED IN THE REACTION KR-84-27 AT 10.6 MEV(AL)NUCLEON/

The cross section, energy distribution and angular distribution of com plex fragments emitted in the reaction Kr-84+ Al-27 at the incident en ergy of 10.6 MeV/nucleon were measured to study the decay mechanism of a highly excited nucleus. Through coincidence measurements between th e light charged particles and the binary decay fragments it is found t hat the pre-scission charge multiplicity is about 80% of the total one . The experimental distributions are well reproduced by the Extended H auser-Feshbach Method (EHFM), introducing a cut-off energy of the exci tation energy of fragments E(cut-off). The fission delay time is deter mined to be 2 x 10(-20) seconds. The role and the physical meaning of E(cut-off) is discussed.