[en] Gamma ray spectrometry of fission product catcherfoils and energy correlation measurements were performed for the photon induced fission of ²³²Th with 12 and 20 MeV bremsstrahlung. The postneutron mass distributions show a third peak for symmetric fission. In the light and heavy mass wings strong fine structures are observed, probably due to odd-even effects. As usually observed, the total preneutron fragment kinetic energy decreases with increasing excitation energy of the compound nucleus in the vicinity of mass 130. For symmetric fission however, the fragment kinetic energies show an increase. Compared to 12 MeV bremsstrahlung induced fission, the number of emitted neutrons increases for fission induced with 20 MeV bremsstrahlung. This can completely be attributed to the heavy fragment. (author)

No abstract available

[en] The emission of light charged particles (LCP) in the photofission of ²³³U, ²³⁵U, ²³⁷Np and ²⁴²Pu with 12, 15 and 20 MeV bremsstrahlung was studied. For the identification of the LCP ΔE-E detectortelescopes were used. We have determined the triton and α particle emission probabilities and the characteristics of the kinetic energy distribution of the α particles. Our measurements show that the excitation energy transferred to the compound nucleus essentially doesn't change the emission probability of the LCP. Our results are compared to sf and thermal neutron induced fission results. They are consistent with the idea that the LCP emission probability is correlated to the deformation energy of the system at scission. (author)

No abstract available