The technique of average resonance neutron capture can lead to the disclosure of sets of nuclear levels known to be complete for certain spin, parity, and excitation-energy ranges. This perceived completeness contains hitherto unrecognized consequences which are shown to present a powerful new tool for nuclear structure studies.

• Received 13 June 1980

DOI:https://doi.org/10.1103/PhysRevLett.45.1077