Photofission mechanism in 232 Th between 7 and 60 MeV

Our objective is to study the main photoabsorption mechanisms in 232 Th between 7 and 60 MeV, namely, Giant Resonances and Quasi-Deuteron, associated to fission decay. We performed electrofission measurements at the linear accelerator of IFUSP. In the analysis, the Virtual Photon Formalism, that related the photofission cross section to the electrofission cross section, was used. In the calculations, the photofission cross section measured at Livermore Laboratory was used. The E2 photoabsorption and quasi-deuteron photoabsorption cross sections were calculated. We concluded that the most important contribution to the electrofission cross section comes from the E1 giant resonance component, the other ones (E2 giant resonance component and quasi-deuteron mechanisms) being 1 or 2% of total electrofission cross section. (author)