Speaker
Description
The so-called “island of inversion” is a region in the nuclear landscape where shell-structure changes are observed and in particular the magic neutron number at N=20 vanishes. For those nuclei at Z=10−12 and around N=20, the shell gap at N=20 quenches and pf-shell intruder configurations become important. We address the question how strong such configurations are for very neutron-rich but Z=9 fluorine isotopes. Such exotic nuclei are produced at the radioactive-ion beam factory (Japan) at beam energies around 250 MeV/u. 29F∗ & 30F are studied in inverse kinematics at the SAMURAI experimental setup by (p,2p) reactions on neon isotopes. The two and one neutron-unbound states, respectively, are investigated in terms of invariant-mass spectroscopy where the decay neutrons are measured explicitly. The resulting excitation-energy spectra are compared to different shell-model based calculations. Moreover, 29F∗ shows a strong two-neutron sequential decay that is also analyzed by means of Jacobi coordinates.
This work is supported by the DFG through grant no. SFB 1245, the BMBF under contract no. 05P15RDFN1, and the GSI-TU Darmstadt cooperation agreement.
