Coulomb excitation of ⁵²Ca

The Coulomb excitation of ⁵²Ca at 240 MeV/nucleon has been measured. In neutron-rich nuclei, it is known that the magic numbers evolve with a neutron-proton ratio (i.e. disappearance at N =8,20)[1]. For Calcium isotopes, ⁵²Ca is supposed to be the doubly magic nucleus with Z=20 and N =32, possible new magic number, based on the relatively high 2⁺₁ energy. And the reduced transition probability B(E2;0⁺₁→2⁺₁ ) has not yet been measured. To disclose the nuclear collectivity, we have measured the B(E2) value of ⁵²Ca with Coulomb excitation.

The experiment was performed by using SAMURAI spectrometer at RIKEN RIBF. The beam at 240 MeV/nucleon impinged on a lead and carbon target, and the reaction residue was identified by using the SAMURAI spectrometer. The de-excitation γ-ray from ⁵²Ca was detected by using the CsI(Na) array CATANA and LaBr₃ detectors.

In the present talk, the Coulomb excitation cross section to the first 2⁺ state of ⁵²Ca will be reported.

[1] O.Sorlin and M.-G.Porquet, Prog. Part. Nucl. Phys. 61,602 (2008)