  The systematic study of fission fragment yields under different initial
conditions provides a valuable experimental benchmark for fission models that
aim to understand this complex decay channel and to predict reaction product
yields. Inverse kinematics coupled to the use of a high-resolution spectrometer
is shown to be a powerful tool to identify and measure the inclusive isotopic
yields of fission fragments. In-flight fusion fission was used to produce
secondary beams of neutron-rich isotopes in the collision of a 238U beam at 24
MeV/u with 9Be and 12C targets at GANIL using the LISE3 fragment-separator.
Unique A,Z,q identification of fission products was attained with the
dE-TKE-Brho-ToF measurement technique. Mass, and atomic number distributions
are reported for the two reactions that show the importance of different
reaction mechanisms for these two targets.
