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The radiative width of the 3/2+ state at 6.793 MeV in 15O has been experimentally determined to be Γγ=0.95+0.60−0.95 eV by intermediate-energy Coulomb excitation. Our result independently supports the recent studies which point to a minor contribution of this state to the astrophysical rate of the 14N(p,γ)15O reaction in the CNO-cycle hydrogen burning in massive stars.

The energy of the first excited state of the very neutron-rich nucleus 30 Ne was determined by proton inelastic scattering. A liquid hydrogen target was bombarded by a beam of radioactive 30 Ne at 48 MeV/nucleon, and energies of the de-excitation γ rays emitted from the excited 30 Ne were measured. The observed transition is likely to be the one from the first 2 + state to the ground state of 30 Ne. The excitation energy, 791(26) keV, is lower than that of 32 Mg, indicating enhancement of deformation as the neutron excess increases in the N =20 isotones. The results indicate that 30 Ne belongs to the ‘island of inversion’.

An isomeric 0+ state at E x = 2.24 MeV in 12Be was found in the projectile fragmentation of 18O at 100 A MeV on a Be target. The excitation energy and the spin assignment were deduced by the measurements of the energies and the angular correlation function of the coincident two γ-rays corresponding to the 0+ → 2+ → 0+ decay, respectively.

Inelastic scattering of the neutron-rich nucleus 12 Be on lead and carbon targets has been studied by measuring de-excitation γ rays in coincidence with scattered 12 Be. The strong γ -ray transition from the state at E x =2.68(3) MeV following E1 Coulomb excitation was observed for the lead target, leading to an assignment of J π =1 − for the excited state. The low excitation energy of this intruder 1 − state and the deduced large B (E1;0 g.s. + →1 − ) value of 0.051(13) e 2 fm 2 provide a consistent picture of the N =8 shell melting in 12 Be.

Inelastic proton scattering exciting the 2 + 1 states in the neutron-rich beryllium isotopes 10,12 Be has been studied in inverse kinematics. From a coupled-channel analysis, the deformation lengths for the 2 + 1 states in 10 Be and 12 Be were determined to be 1.80±0.25 fm and 2.00±0.23 fm respectively, indicating that a tendency towards strong quadrupole deformation is preserved for these nuclei and that the singly-closed shell structure does not prevail in 12 Be. A quantitative analysis based on shell model calculations supports this picture.