Recoil distance half-life measurements of the excited states in 145Sm
A.M. El-Badry1 - T. Kuroyanagi1 - S. Mitarai1 - A. Odahara1 - Y. Gono1 - S. Morinobu1 - K. Ogawa2
1 Department of Physics,Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka
812-8581, Japan
2 Department of physics, Chiba University, Chiba 263, Japan
Received: 9 September 1997 / Revised version: 12 June 1998 Communicated by K. Nakai
Abstract
A recoil distance method was used
to measure half-lives of the excited states of 145Sm.
The reaction used was
139La(10B, 4n)145Sm.
A plunger system was used.
Half-lives were determined
for two excited states for the first time.
The yrast 27/2+ state was found
to have a half-life of 1.1 
0.2 ns
corresponding to the retardation of 3.1 
10-4
comparing with the single particle estimate of M1.
The excitation energy of this state was well reproduced
by the shell model calculation having a mixed configuration
of [
{h11/2(g7/2)-2 (d5/2)-1 }10-,
f7/2] +
[{h11/2(g7/2)-1}9-,h9/2].
Another retarded E1 transition was also found
in a decay of a 21/2+ state.
Its retardation was 1.6 10-4
comparing with the single particle value.
PACS
21.10.-kProperties of nuclei; nuclear energy levels -
27.60.+j
Copyright Springer-Verlag
