Fission studies at VAMOS
Résumé
Inverse kinematics is a new tool to study nuclear fission. Its main advantage is
the possibility to measure with an unmatched resolution the atomic number of fission
fragments, leading to new observables in the properties of fission-fragment
distributions. In addition to the resolution improvement, the study of fission based on
nuclear collisions in inverse kinematics beneficiates from a larger view with respect to
the neutron-induced fission, as in a single experiment the number of fissioning
systems and the excitation energy range are widden. With the use of spectrometers,
mass and kinetic-energy distributions may now be investigated as a function of the
proton and neutron number sharing. The production of fissioning nuclei in transfer
reactions allows studying the isotopic yields of fission fragments as a function of the
excitation energy. With the access of kinematics properties, the charge polarisation of
fragments at scission is now revealed with high precision, and it is shown that it
cannot be neglected, even at higher excitation energies. Results on fissioning systems
238U, 239Np, 240Pu, 244Cm, obtained in transfer reactions are presented, together with
the fusion reaction leading to the compound nucleus 250Cf at an excitation energy of
45MeV.