Community Research and Development Information Service - CORDIS


Preliminary results of a search for the shape isomers of 239U and 233Th are reported. Neutron-capture experiments with a timing resolution for gamma-gamma coincidences of about 1 ns were performed to investigate the expected delayed gamma-decay branch in both compound nuclei. In the case of 239U, the well known 721 eV neutron resonance was investigated. This has the largest fission width compared to its neighbours, and is assumed to be a a good candidate to decay to an isomeric state in the second well. For 233Th, the relative delayed gamma-yield of all s-wave neutron resonances between 50 eV and 4.0 keV was analysed, and an intermediate structure due to coupling between class-I to class-II states was sought.

Additional information

Authors: OBERSTEDT S ET AL., JRC Geel (BE);THEOBALD J P, Institut für Kernphysik, Darmstadt (DE)
Bibliographic Reference: Paper presented: Seminar on Fission, Pont d'Oye (BE), Oct. 23-25, 1991
Availability: Available from (1) as Paper EN 36449 ORA
Record Number: 199111595 / Last updated on: 1994-12-02
Original language: en
Available languages: en