First Observation of Backbending in an Actinide Nucleus

W. Spreng; F. Azgui; H. Emling; E. Grosse; R. Kulessa; Ch. Michel; D. Schwalm; R. S. Simon; H. J. Wollersheim; M. Mutterer; J. P. Theobald; M. S. Moore; N. Trautmann; J. L. Egido; P. Ring

doi:10.1103/PhysRevLett.51.1522

First Observation of Backbending in an Actinide Nucleus

W. Spreng, F. Azgui, H. Emling, E. Grosse, R. Kulessa, Ch. Michel, D. Schwalm, R. S. Simon, H. J. Wollersheim, M. Mutterer, J. P. Theobald, M. S. Moore, N. Trautmann, J. L. Egido, and P. Ring

Phys. Rev. Lett. 51, 1522 – Published 24 October 1983

Abstract

The yrast bands in ${}^{242}{Pu}$ and ${}^{244}{Pu}$ have been studied up to spin $26^{+}$ by Coulomb excitation using ${}^{208}{Pb}$ beams of 5.1 and 5.3 MeV/u. In the case of ${}^{244}{Pu}$ a pronounced backbending has been observed for the first time in an actinide nucleus. Microscopic calculations are presented which indicate that the observed anomalies in the yrast sequences of both nuclei are due to alignment effects in the $i_{\frac{13}{2}}$ proton shell.

Received 18 August 1983

DOI:https://doi.org/10.1103/PhysRevLett.51.1522

Authors & Affiliations

W. Spreng, F. Azgui, H. Emling, E. Grosse, R. Kulessa^*, Ch. Michel, D. Schwalm^†, R. S. Simon, and H. J. Wollersheim

Gesellschaft für Schwerionenforschung, D-6100 Darmstadt, Germany

M. Mutterer and J. P. Theobald

Institut für Kernphysik, Technische Hochschule Darmstadt, D-6100 Darmstadt, Germany

M. S. Moore

Los Alamos Scientific Laboratory, Los Alamos, New Mexico 87544

N. Trautmann

Institut für Kernchemie, Universität Mainz, D-6500 Mainz, Germany

J. L. Egido^‡ and P. Ring

Physikalisches Institut, Technische Universität München, D-8046 Garching, Germany

^*Permanent address: Institute of Physics, Jagellonian University, Krakow, Poland.
^†Permanent address: Physikalisches Institut, Universität Heidelberg, Heidelberg, Germany.
^‡Permanent address: Departamento de Física Teórica, Universidad Autónoma de Madrid, Madrid, Spain.