2018 Impact factor 2.481
Hadrons and Nuclei
Eur. Phys. J. A 16, 409-414 (2003)
DOI: 10.1140/epja/i2002-10110-1

Multiple Coulomb excitation of a $\chem{^{70}Ge}$ beam and the interpretation of the $\chem{0_{2}^{+}}$ state as a deformed intruder

M. Sugawara1, Y. Toh2, T. Czosnyka3, M. Oshima2, T. Hayakawa2, H. Kusakari4, Y. Hatsukawa2, J. Katakura2, N. Shinohara2, M. Matsuda2, T. Morikawa5, A. Seki6 and F. Sakata6

1  Chiba Institute of Technology, Narashino, Chiba 275-0023, Japan
2  Japan Atomic Energy Research Institute, Tokai, Ibaraki 319-1195, Japan
3  Heavy Ion Laboratory, Warsaw University, Warsaw PL-02097, Poland
4  Chiba University, Inage-ku, Chiba 263-8522, Japan
5  Kyushu University, Hakozaki, Fukuoka 812-8581, Japan
6  Department of Mathematical Sciences, Ibaraki University, Mito, Ibaraki 310-8512, Japan

sugawara@pf.it-chiba.ac.jp

(Received: 2 September 2002 / Revised version: 4 November 2002 / Published online: 25 February 2003)

Abstract
Electromagnetic properties of the low-lying states in a $\chem{^{70}Ge}$ nucleus were studied through the multiple Coulomb excitation of a $\chem{^{70}Ge}$ beam with a $^{\rm nat}$Pb target. Relative $\gamma$-ray intensities were measured as a function of emission angle relative to the scattered projectile. Sixteen E2 matrix elements, including diagonal ones, for 6 low-lying states have been determined using the least-squares search code GOSIA. The expectation values $\langle Q^2$ $\rangle$ of 0 1+ and 0 2+ states in $\chem{^{70}Ge}$ are compared with those in $\chem{^{72,74,76}Ge}$. Simple mixing calculations indicate that the 0 2+ states in $\chem{^{70}Ge}$ and $\chem{^{72}Se}$ can be treated as deformed intruder states. It is shown that the deformed intruder becomes the ground state in $\chem{^{74}Kr}$. These interpretations of the 0 2+ states in this region are compared with the potential-energy surface calculations by the Nilsson-Strutinsky model, which allow to interpret the experimental results in a qualitative way from the theoretical point of view.

PACS
25.70.De - Coulomb excitation.
21.10.Ky - Electromagnetic moments.
23.20.-g - Electromagnetic transitions.

© Società Italiana di Fisica, Springer-Verlag 2003