No abstract

The degree of collectivity in the neutron-rich nuclei 32 Mg and 34 Mg has been determined via intermediateenergy Coulomb excitation in inverse kinematics. Measured energies of the first excited 2 + states and reduced electric quadrupole transition probabilities B(E2; 0 + g.s. → 2 + 1 ) are presented for 32 Mg and 34 Mg. The results agree with previous measurements and confirm the placement of both nuclei within the "island of inversion."

The nucleus 52 Fe with ͑N = Z =26͒ has been investigated using intermediate-energy Coulomb excitation in inverse kinematics. A reduced transition probability of B͑E2;0 1 + → 2 1 + ͒ = 817͑102͒ e 2 fm 4 to the first excited 2 + state at 849.0(5) keV was deduced. The increase in excitation strength B͑E2 ↑ ͒ with respect to the even-mass neighbor 54 Fe (B͑E2 ↑ ͒ = 620͑50͒ e 2 fm 4 ) agrees with shell-model expectations as the magic number N =28 is approached. This measurement completes the systematics of reduced transition strengths to the first excited 2 + state for the even-even N = Z nuclei up to mass A = 56.