Production Of Exotic Nuclear Isomers In Multi-Nucleon Transfer Reactions

This paper reports on recent work using multinucleon transfer reactions to populate metastable states in neutron-rich rare-earth and transitional nuclei with A similar to 180-200. The use of a position sensitive gas-filled detector CHICO allowed the directions of the binary fragments to be measured, thereby enabling event-by-event Doppler corrections to be made for the prompt, in-beam transitions depopulating the nuclei of interest. By using the temporal calibration provided by (i) the measurement of the binary reaction fragments and (ii) the natural pulsing of the cyclotron beam, transitions from metastable states with lifetimes in the nano-to microsecond regime could be identified. The complementarity of this technique with the novel use of relativistic projectile fragmentation reactions is outlined, together with potential future avenues for this research, with a particular emphasis on the population of exotic isomeric states at high angular momentum and excitation energy values.Time of flight difference versus laboratory angle for the binary fragments of the reaction of an 850 MeV Xe-136 beam on a thin, self-supporting Pt-198 target as measured in CHICO.