Experimental cross sections in fission of natural uranium induced by a neutron spectrum of 12.4-MeV average energy

Yields of fission products are essential for designing Radioactive Ion Beam facilities and extracting cross section data to refine reaction models. This work reports the results of irradiations of natural uranium targets with a continuous spectrum of fast neutrons. A rapid transport system has been used to bring the targets in front of two segmented Clover detectors operated in coincidence. Decay gamma-ray spectroscopy of the fission products has allowed for cross sections to be obtained in 61 mass chains, either as independent or as cumulative for the chain. Interpolation versus mass number together with the assumption of a Gaussian distribution of isobars enable cross sections to be evaluated in nearly 80 mass chains. The measurement demonstrates the power of the detectors for twofold gamma-gamma events following beta-decay and indicates that new fission product decay data could be obtained with a dedicated set up.