Fission hindrance in 200Pb measured from giant dipole resonance γ-ray emission -: art. no. 014611

High-energy gamma rays from the decay of the giant-dipole resonance built on excited states were measured in coincidence with fission fragments for the 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 compound 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 the effects of nuclear dissipation. Calculations with nuclear viscosity parameter of gamma (i)=3 inside the saddle point and gamma (o)=10 for the saddle to scission decay describe the experimental data.