'Safe' Coulomb Excitation of {sup 30}Mg

We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient {gamma} spectrometer MINIBALL. Using {sup 30}Mg ions accelerated to an energy of 2.25 MeV/u together with a thin {sup nat}Ni target, Coulomb excitation of the first excited 2{sup +} states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation {gamma}-ray yields the B(E2;0{sub gs}{sup +}{yields}2{sub 1}{sup +}) value of {sup 30}Mg was determined to be 241(31)e{sup 2} fm{sup 4}. Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the theoretical conjecture that the neutron-rich magnesium isotope {sup 30}Mg resides outside the 'island of inversion'.