Deformations of Ne isotopes in the island of inversion are determined by the folding model description of the interaction cross sections measured for ${}^{28-32}$Ne isotopes incident on a ${}^{12}$C target at 240 MeV/nucleon, using the Melbourne g-matrix interaction and the nuclear densities calculated by antisymmetrized molecular dynamics (AMD). The double folding model with the AMD density well reproduces the measured interaction cross sections, if the tail correction is made to the AMD density for ${}^{31}$Ne. The quadrupole deformation determined is around 0.4 in the island of inversion and ${}^{31}$Ne is a halo nucleus with large deformation. We propose the Woods-Saxon model with the AMD deformation and a suitably chosen parametrization set as an approximate but simple method to reproduce the AMD density with the tail correction. The angular momentum projection is essential to obtain the large deformation in the island of inversion. Effects of the pairing correlation are investigated.

• Received 17 November 2011

DOI:https://doi.org/10.1103/PhysRevC.85.064613