NUCLEAR ENERGY LEVEL SPACING DISTRIBUTIONS IN EVEN IRON ISOTOPES
CEC, Joint Research Centre, Geel Establishment,
Central Bureau for Nuclear Measurements, B-2440 Geel, Belgium
Georges J. Vanpraet
University of Antwerp, RUCA, B-2020 Antwerp, Belgium
Nearest level spacing distributions of s-wave neutron resonances in 54,56 and 58Fe have been studied. It is found that for 54Fe and 58Fe the distribution of the observed individual level spacings deviates from a Wigner distribution. For 56Fe such a deviation could not be verified in an unambigous way. The reason for this may be that in 54Fe and 58Fe we are dealing with doorway resonances whereas in 56Fe a mixing of 3p-2h energy levels belonging to neighbouring doorway state resonances is already effective.
KEYWORDS: Neutron resonances, level spacing distributions, even Fe-isotopes