Pre-scission emission and evaporation residues survival probability in the reaction Cl-37+Sn-120 at 187 MeV

Light particles spectra in coincidence with fission fragments have been measured for the reaction 187 MeV Cl-37 on Sn-120 populating Ho-157 compound nuclei at the excitation energy E-x = 85 MeV. The experimental neutron pre-scission multiplicity for symmetric splitting is two times larger than the statistical model estimate. The experimental multiplicity is reproduced by calculations in which a fission delay, in agreement with systematics, is introduced. This empirical fission delay produces a sizeable increase, with respect to the standard statistical model estimate, of the survival probability against fission for nuclei with angular momentum around J similar to 75 (h) over bar. The importance of this effect in the population of superdeformed and hyperdeformed structures in the evaporation residues is discussed.