STUDY OF PRESCISSION EVAPORATION FOR KR-84-27 AT 10.6 MEV(AL)U USING 3-PI-PHOSWICH DETECTOR SYSTEM/

We measured the pre-scission multiplicity of charged particle for tile system of Kr-84+ Al-27 at 10.6 MeV/u. The charge multiplicity of pre- scission is about 80% of the total charge multiplicity, which is about ten times as large as that calculated by a statistical model code (GE MINI). To reproduce the pre-scission multiplicity it is essential to i ntroduce a fission delay time of the order of 10(-20) sec. it makes, h owever, the significant suppression of the binary fragment cross secti ons. To reproduce both cross section of binary fragments and pre-sciss ion particle multiplicity simultaneously with the code, the pre-scissi on particles should not be emitted at the pre-saddle point, but betwee n the saddle and scission points. The another explanation is that the composite system is formed between the saddle and scission points.