https://doi.org/10.1007/s10050-000-4503-0
Level structure of 123Cs observed from 123Ba decay and described using the IBFM and CQPC models
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
Institut de Physique Nucléaire, IN2P3-CNRS, B.P. 1, 91406, Orsay-Cedex, France
4
I.A.A. Université Libre de Bruxelles, Boulevard du Triomphe, 1050, Brussels, Belgium
5
Institute of Nuclear Research, Pf. 51, 4001, Debrecen, Hungary
6
Departamento de Física Atómica Molecular y Nuclear, Universidad de Sevilla, Aptdo. 1065, 41080, Sevilla, Spain
7
Departamento de Física Aplicada, ESII, Universidad de Sevilla, Sevilla, Spain
8
Institute of Experimental Physics, Warsaw University, Hoża 69, 00681, Warsaw, Poland
* e-mail: gizon@isn.in2p3.fr
Received:
3
January
2000
Revised:
25
February
2000
Published online: 11 September 2013
The decay of 123Ba to 123Cs has been studied with mass-separated sources. Singles spectra of γ-rays, X-rays and conversion electrons as well as γ - γ - t, γ - e − - t, and X - e − - t coincidences were recorded. A level scheme of 123Cs has been constructed including 26 new excited states and 82 transitions. The existence of a I π = 11/2−, T 1/2 = 1.7 s isomer, bandhead of the h 11/2 band, is confirmed. Its excitation energy equals 156.3 keV. A new T 1/2 = 114 ns isomer has been established at 232 keV using the in-beam recoil catcher technique. It is assigned to the I π = 9/2+ bandhead of the gpg 9/2 band. Collective bands based on the 1/2+ ground state and first 3/2+ excited state are proposed. The level structure is described in the frame of the interacting boson-fermion and core-quasiparticle coupling models.
PACS: 21.10.Re Collective levels – / 23.20.Lv Gamma transitions and level energies – / 23.20.Nx Internal conversion – / 21.60.Ev Collective models – / 27.60.+j 90 ≤ A ≤ 149 –
© Società Italiana di Fisica and Springer-Verlag, 2000