G. Lhersonneau
Shape coexistence near the double-midshell nucleus 111 Rh
G. Lhersonneau1 - B. Pfeiffer2 - J. Alstad3 - P. Dendooven1 - K. Eberhardt2 - S. Hankonen1 - I. Klöckl2 - K.-L. Kratz2 - A. Nähler2 - R. Malmbeck4 - J.P. Omtvedt3 - H. Penttilä1 - S. Schoedder2 - G. Skarnemark4 - N. Trautmann2 - J. Äystö1
1 Department of Physics, University of Jyväskylä, P.O.Box. 35,
FIN-40351, Jyväskylä, Finland
2 Institut für Kernchemie, Universität Mainz, Fritz-Strassmann-Weg 2, D-55128
Mainz, Germany
3 Department of Chemistry, University of Oslo, N-0315 Oslo, Norway
4 Department of Nuclear Chemistry, Chalmers University of Technology, S-41296
Göteborg, Sweden
Received: 25 June 1997 / Revised version: 10 September 1997 Communicated by P. Armbruster
Abstract
The decay of 111Ru obtained from fast on-line chemical and
mass separation has been investigated by 
-
-t and
- coincidence techniques. Earlier spin and
parity assignments of 111Rh levels based
on extrapolations of level systematics are confirmed. In particular, the
K=1/2 intruder band is supported by the hindrance of E2 transitions
between deformed and spherical states and
enhancement of intraband E2 transitions.
The excitation energies
of intruder band members in Rh isotopes
show a minimum at 109Rh64, with two neutrons less than
111Rh at the N=66 midshell. This trend,
which differs from the one in the higher-Z neighbouring
elements Ag and Cd with minima at N=66, follows the evolution of
deformation observed in the lower-Z elements Ru and Mo.
PACS
27.60.+j 
-
21.10.Tg Lifetimes -
23.20.Lv Gamma transitions and level energies
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