The population of metastable states as a probe of relativistic-energy fragmentation reactions

A.M. Denis Bacelar, A.M. Bruce, Zs. Podolyák, N. Al-Dahan, M. Górska, S. Lalkovski, S. Pietri, M.V. Ricciardi, A. Algora, N. Alkhomashi, J. Benlliure, P. Boutachkov (+44 others)
2013 Physics Letters B  
88 Ra and 215 89 Ac following the projectile fragmentation of a 1 A.GeV 238 U beam by a 9 Be target at GSI Helmholtzzentrum für Schwerionenforschung. The fragments were separated in the fragment separator (FRS) and identified by means of energy loss and time-of-flight techniques. They were brought to rest at the centre of the RISING gamma-ray detector array and intensities of gamma-rays emitted in the decay of isomeric states with half-lives between 100 ns and 40 µs and spin values up to 55/2
more » ... values up to 55/2 were used to obtain the corresponding isomeric ratios. The data are compared to theoretical isomeric ratios calculated in the framework of the abrasion-ablation model. Large experimental enhancements are obtained for high-spin isomers in comparison to expected values.
doi:10.1016/j.physletb.2013.05.033 fatcat:uf24bape2vh6favztgtio3rqlq