2019 Impact factor 2.176
Hadrons and Nuclei
Eur. Phys. J. A 7, 149-153

New insight in the level structure of 153Er

C. Foin1 - F. Farget1 - A. Gizon1 - D. Santos1 - D. Barnéoud1 - J. Genevey1 - J. Gizon1 - P. Paris2 - M. Ashgar1 - A. P\lochocki3

1 Institut des Sciences Nucléaires, IN2P3-CNRS/Université Joseph Fourier, 38026, Grenoble Cedex, France
2 CSNSM,IN2P3-CNRS, Bt.104, 91405 Campus Orsay, France
3 Institute of Experimental Physics, 00-681, Warsaw, Poland

Received: 8 November 1999 / Revised version: 13 December 1999 Communicated by B. Herskind

Abstract
The high-spin level structure of the 153Er nucleus has been reinvestigated by in-beam $\gamma$-ray and electron spectroscopy with (14N,pxn) reaction. Excitation energies, spin and parity assignments are unambiguously established for the two lowest isomers $T_{1/2}\simeq 380$ ns and $T_{1/2}\simeq 10$ ns. The characteristics of the third one ( $T_{1/2}\simeq 250$ns) at 5.2 MeV are still questionable but its main decay modes are better known. An extension of the level scheme is proposed up to 8.4 MeV.Experimental results have been discussed in terms of shell model multiplets and compared with the other structures observed in N=85 neighbouring nuclei.

PACS
21.10.Pc Single-particle levels - 23.20.Lv Gamma transitions and level energies - 27.70.+q $150 \leq A \leq 189$


Copyright Società Italiana di Fisica, Springer-Verlag 2000