“Safe” Coulomb Excitation of 30Mg

We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient 𝛾 spectrometer MINIBALL. Using
30
Mg
ions accelerated to an energy of 2.25 MeV/𝑢 together with a thin
nat
Ni
target, Coulomb excitation of the first excited 2+ states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation 𝛾-ray yields the 𝐵⁡(𝐸⁢2;0+
gs →2+
1) value of
30
Mg
was determined to be 241⁢(31)⁢𝑒2 fm4. 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
30
Mg
resides outside the “island of inversion.”

Authors: . Niedermaier, H. Scheit, V. Bildstein, H. Boie, J. Fitting, R. von Hahn, F. Köck, M. Lauer, U. K. Pal, H. Podlech, R. Repnow, D. Schwalm, C. Alvarez, F. Ames, G. Bollen, S. Emhofer, D. Habs, O. Kester, R. Lutter, K. Rudolph, M. Pasini, P. G. Thirolf, B. H. Wolf, J. Eberth, G. Gersch, H. Hess, P. Reiter, O. Thelen, N. Warr, D. Weisshaar, F. Aksouh, P. Van den Bergh, P. Van Duppen, M. Huyse, O. Ivanov, P. Mayet, J. Van de Walle, J. Äystö, P. A. Butler, J. Cederkäll, P. Delahaye, H. O. U. Fynbo, L. M. Fraile, O. Forstner, S. Franchoo, U. Köster, T. Nilsson, M. Oinonen, T. Sieber, F. Wenander, M. Pantea, A. Richter, G. Schrieder, H. Simon, T. Behrens, R. Gernhäuser, T. Kröll, R. Krücken, M. Münch, T. Davinson, J. Gerl, G. Huber, A. Hurst, J. Iwanicki, B. Jonson, P. Lieb, L. Liljeby, A. Schempp, A. Scherillo, P. Schmidt, G. Walter

Doi: 10.1103/PhysRevLett.94.172501

Issue number:

Journal: Phys. Rev. Lett.

Page number: 172501

Published on: 2005-05-04

Year: