Cross section for 234U photofission in the energy region 5-9 MeV

The reference method has been employed to measure the cross section for 234U photofission over the energy region between 4.7 and 9.0 MeV with a step of 25 keV in the subbarrier region. The measurements have been performed in a beam of bremsstrahlung photons from the microtron installed at the Institute of Physics and Power Engineering (Obninsk). By invoking the previously measured angular distributions of fragments from 234U photofission, the partial cross sections for the JπK=1-0 and 1-1 photofission channels have been determined from the total cross section as functions of the excitation energy. The partial cross sections measured in this way have then been used as inputs for a theoretical analysis of the subbarrier photofission of 234U. This analysis relies on the one-dimensional model employing a two-humped barrier and taking into account the damping of vibrational states in the second potential well. The parameters of the two fission barriers have been estimated on this basis. The results are compared with those of previous measurements