Identification of a possible new island of inversion, O. Tarasov, NSCL / Michigan State University, East Lansing, Michigan, USA − Experiments at the NSCL have used projectile fragmentation coupled with the two-stage separation technique to explore the properties of very neutron-rich nuclei. In a recent experiment, production cross sections for a large number of neutron-rich nuclei produced from the fragmentation of a 76Ge beam at 132 MeV/u with beryllium and tungsten targets were measured, including 15 new isotopes of the elements 17 ≤ Z ≤ 25. Enhanced cross sections of several new nuclei as compared to a simple thermal evaporation framework, which has been shown to describe similar production cross sections, indicate that nuclei in the region around 62Ti might be more stable than predicted by current mass models. This could indicate the existence of a new island of inversion [1].


In the most recent experiment, a newly-developed primary beam of 82Se at 140 MeV/u was used to extend these measurements of production cross sections. Several isotopes of the elements 22 ≤ Z ≤ 26 have been observed for the first time. Production cross sections of neutron-rich nuclei produced by fragmentation of a 82Se beam, and their analysis to elucidate the possible new island of inversion will be presented.


[1] O. B. Tarasov et al., Phys. Rev. Lett 102 (2009) 142501.