Nuclear viscosity of hot rotating ²⁴⁰Cf

The absolute γ-ray/fission multiplicities from hot rotating ²⁴⁰Cf, populated at seven bombarding energies using the reaction ³²S+²⁰⁸Pb, are reported. Statistical model calculations including nuclear dissipation have been performed to extract the dependence of the nuclear viscosity on temperature and/or nuclear deformation. The extracted nuclear dissipation coefficient is found to be independent of temperature. Large dissipation during the saddle to scission path provides a good fit to the γ-ray spectra.