Coulomb excitation of Mg-31

• Published in: Physics letters. B Vol. 700; no. 3-4; p. 181
• Main Authors: Seidlitz, M., Muecher, D., Reiter, P., Bildstein, V., Blazhev, A., Bree, N., Bruyneel, B., Cederkäll, Joakim, Clement, E., Davinson, T., Van Duppen, P., Ekström, Andreas, Finke, F., Fraile, L. M., Geibel, K., Gernhaeuser, R., Hess, H., Holler, A., Huyse, M., Ivanov, O., Jolie, J., Kalkuehler, M., Kotthaus, T., Kruecken, R., Lutter, R., Piselli, E., Scheit, H., Stefanescu, I., de Walle, J. Van, Voulot, D., Warr, N., Wenander, F., Wiens, A.
• Format: Journal Article
• Language: English
• Published: 2011
• Subjects: Coulomb excitation; Fysik; inversion; Island of; ISOL; Natural Sciences; Naturvetenskap; Physical Sciences; Reduced transition matrix element; Subatomic Physics; Subatomär fysik
• ISSN: 0370-2693
• DOI: 10.1016/j.physletb.2011.05.009

The ground state properties of Mg-31 indicate a change of nuclear shape at N = 19 with a deformed J(pi) = 1/2(+) intruder state as a ground state, implying that Mg-31 is part of the "island of inversion". The collective properties of excited states were the subject of a Coulomb excitation experiment at REX-ISOLDE, CERN, employing a radioactive Mg-31 beam. De-excitation gamma-rays were detected by the MINIBALL gamma-spectrometer in coincidence with scattered particles in a segmented Si-detector. The level scheme of Mg-3I was extended. Spin and parity assignment of the 945 keV state yielded 5/2(+) and its de-excitation is dominated by a strong collective M1 transition. Comparison of the transition probabilities of Mg-30,Mg-31,Mg-32 establishes that for the N = 19 magnesium isotope not only the ground state but also excited states are largely dominated by a deformed pf intruder configuration. (C) 2011 Elsevier B.V. All rights reserved.