Program - Brookhaven National Laboratory

Correlations Between Nuclear Charge Radii, E0 Transitions and Summed M1 Strengths
P. Van Isacker
GANIL, CEA/DSM-CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5, France
A systematic study of energy spectra throughout the rare-earth region (even-even nuclei from 58Ce to 74W)
is carried out in the framework of the interacting boson model (IBM), which gives a global description of the
spherical-to-deformed shape transition in the different isotopic chains. The resulting IBM Hamiltonian is
then used for the calculation of nuclear charge radii (including isotope and isomer shifts) and E0 transitions
with consistent operators for the two observables [1,2]. Following ideas developed by Ginocchio [3], an
additional correlation is pointed out between both of these properties (i.e., charge radii and E0 transitions)
with the summed M1 strength from the ground state of even-even nuclei to the scissors mode. This leads to
correlation plots between isotope shifts and summed M1 strength differences on the one hand, and between
ρ 2 (E0) values and summed M1 strengths on the other hand. Examples of such correlation plots are shown
for rare-earth nuclei.
[1] S. Zerguine, P. Van Isacker, A. Bouldjedri, and S. Heinze, Phys. Rev. Lett. 101, 022502 (2008). [2] S.
Zerguine, P. Van Isacker, and A. Bouldjedri, Phys. Rev. C 85, 034331 (2012). [3] J.N. Ginocchio, Phys.
Lett. B 265, 6 (1991).
DD 4 4:40 PM
First Total Absorption Spectroscopy Measurement of the Beta Decay of 139 Xe
A. Fijalkowska, M. Karny, K. Mienik, Faculty of Physics, University of Warsaw, Warsaw, PL 00-681,
Poland. K.P. Rykaczewski, M. Wolinska-Cichocka, C.J. Gross, J. W. Johnson, C. Jost, D. Stracener,
ORNL, Oak Ridge, TN 37830, USA,. R.K. Grzywacz, L. Cartegni, K.C. Goetz, M. Al-Shudifat,
University of Tennessee, Knoxville, TN 37996, USA. R. Goans, M. Madurga, D. Miller, S.W. Padgett,
S.V. Paulauskas, E. Spejewski, ORAU, Oak Ridge, TN 37830, USA. B.C. Rasco, E. Zganjar, Louisiana
State University, Baton Rouge, LA 70803, USA. J.H. Hamilton, A.V. Ramayya, Dept. of Physics and
Astronomy, Vanderbilt University, Nashville, TN 37235, USA.
The Modular Total Absorption Spectrometer (MTAS) has been recently constructed and commissioned at
the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory [1]. The main
scientific goal of MTAS is to determine the true beta-decay feeding and following gamma radiation pattern
for the decays of fission products. This is important not only for understanding of the relevant nuclear
structure and beta decay processes, but also for the determination of the decay heat release during a
nuclear fuel cycle. Existing theoretical simulations of decay heat show, in fact, significant deviations from
experimental data [2-4]. These discrepancies are believed to be partially due to the incorrect or incomplete
beta decay schemes. In this contribution we would like to present the results of the measurement of 139 Xe
beta decay, which was identified among ”most wanted” for the analysis of decay heat in nuclear reactors
[2]. 139 Xe nuclei, among others [5], were produced at HRIBF in the proton-induced fission of 238 U, mass
separated and implanted onto a moving tape, which periodically transported the activity to the centre of
MTAS. The results and their impact on the decay heat calculations will be presented and discussed.
[1] M.Wolinska-Cichocka et al., contribution to this conference [2] “Assessment of fission product decay
data for decay heat calculations” OECD 2007, NEA No 6284, vol. 25, ISBN 978-92-64-99034-0 [3] A.
Algora et al., Phys. Rev. Lett., 105, 202501, 2010. [4] K. P. Rykaczewski, Physics 3, 94, 2010. [5] M.
Karny et al., contribution to this conference.
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