Abstract
This article reports on results of an experimental search for ground state shell inversion in the neutron-unbound N=7 isotones He9 and Li10. Two different radioactive ion beams (Be11, Elab=44MeV/u and B12, Elab=45MeV/u) impinging on a beryllium target were used to directly and selectively populate unbound states of a given in the nuclides of interest. Be(Be11,He8+n) and Be(B12,He8+n) reactions populated unbound states in He9. Fragments and neutrons were detected in coincidence to reconstruct the decay energy of He9 using invariant mass spectroscopy. Similarly, Be(Be11,Li9+n) and Be(B12,Li9+n) reactions were used to populate unbound states in Li10, and the time-of-flight method was used to determine the relative velocity of the Li9 fragments and neutrons in coincidence. Various states in both He9 and Li10 were observed and characterized. The data indicate possible ground state shell inversion in both cases.
| Original language | English |
|---|---|
| Article number | 014325 |
| Journal | Physical Review C |
| Volume | 102 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jul 2020 |
| Externally published | Yes |
Funding
The authors would like to thank all members of the MoNA Collaboration, and all of the NSCL/FRIB staff that contributed to the success of this experiment. This material is based upon work supported by the Department of Energy National Nuclear Security Administration through the Nuclear Science and Security Consortium under Award Number(s) DE-NA0003180 and/or DE-NA0000979, and the National Science Foundation Grants No. PHY-1205357, No. PHY-1613188, No. PHY-1713522, No. PHY-1713956, and No. PHY-1744043. The operation of the National Superconducting Cyclotron Laboratory at Michigan State University is supported by the NSF under Grant No. PHY-1565546.