  The production of light and intermediate-mass nuclides formed in the reaction
1H+238U at 1 GeV was measured at the Fragment Separator (FRS) at GSI,
Darmstadt. The experiment was performed in inverse kinematics, shooting a 1 A
GeV 238U beam on a thin liquid-hydrogen target. 254 isotopes of all elements in
the range from Z=7 to Z=37 were unambiguously identified, and the velocity
distributions of the produced nuclides were determined with high precision. The
results show that the nuclides are produced in a very asymmetric binary decay
of heavy nuclei originating from the spallation of uranium. All the features of
the produced nuclides merge with the characteristics of the fission products as
their mass increases.
