NUCLEAR-LEVELS IN TH-233 EXCITED BY NEUTRON-CAPTURE

The excited levels in 233Th have been studied using thermal and average resonance neutron capture in 232Th. 2 keV and 24 keV neutron capture has been investigated at the Brookhaven HFBR filtered beam facility. Conversion electrons and low energy γ-rays following thermal neutron capture have been measured at the ILL, Grenoble. From the combination of these data a level scheme of 233Th is proposed, which includes all low-spin states up to about 900 keV. Nine Nilsson configurations have been identified. Several rotational bands are explained as β, γ and octupole vibrational excitations. β-vibrational bands coupled to the [631 ↓] Nilsson states could be identified from the observation of transitions having strong E0 admixtures. © 1979.