Fission hindrance in Pb-200 measured from giant dipole resonance gamma-rayemission - art. no. 014611

High-energy gamma rays from the decay of the giant-dipole resonance built o n excited states were measured in coincidence with fission fragments for th e reaction F-19+Ta-181-->Pb-200 at bombarding energies 161 and 181 MeV. The gamma -ray spectra containing contributions from the decay of the hot comp ound Pb-200 nucleus on its way to fission and from the decay of the fission fragments were analyzed using the statistical model modified to include th e effects of nuclear dissipation. Calculations with nuclear viscosity param eter of gamma (i)=3 inside the saddle point and gamma (o)=10 for the saddle to scission decay describe the experimental data.