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# Nuclear structure of 189Tl states studied via \beta^{{+}}_{} /EC decay and laser spectroscopy of 189m+gPb

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Oliver Lodge Laboratory, University of Liverpool, L69 7ZE, Liverpool, UK
(Impact Factor: 2.42). 01/2009; 39(1). DOI: 10.1140/epja/i2008-10693-3

ABSTRACT The

$\beta^{{+}}_{}$
/EC decay of 189m, gPb has been studied at the ISOLDE facility using nuclear spectroscopy and in-source laser spectroscopy. A level scheme of 189Tl has been built from

$\gamma$
-

$\gamma$
coincidence relationships and information on the feeding of some excited levels of 189Tl provided by the hyperfine spectra obtained from laser ionization. The half-lives of both the 13/2+ and 3/2-189Pb isomers have been estimated to be T
1/2 = 50±3 s and T
1/2 = 39±8 s, respectively. Calculations have been performed for different oblate and prolate nuclear deformations using an axial-rotor coupled to one-quasiparticle model, a structure has been suggested for the low-lying levels of the 189Tl nucleus.

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Available from: Ulli Koester, Jul 07, 2015
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##### Article: Decay of the 9/2^{-} isomer in^{181} Tl and mass determination of low-lying states in^{181} Tl,^{177} Au, and^{173} Ir
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ABSTRACT: A detailed spectroscopic study of the neutron-deficient isotope 181Tl and the daughter of its α decay, 177Au, has been performed in the complete fusion reaction 40Ca+144Sm→184Pb* at the velocity filter SHIP (GSI). The mass excess, excitation energy, and decay scheme of the isomeric 1.40(3) ms, 9/2- intruder state in 181Tl have been established for the first time. These results solve a long-standing puzzle of the unrealistically large reduced α-decay width of this isomer. Based on this, the previously unknown masses of the long-lived isomeric states in 177Au and 173Ir have been derived. In turn, it now allows the excitation energies of previously identified bands in 177Au and 173Ir to be deduced and compared with theoretical predictions. First measurements of α-decay branching ratios for 181Tlm and 177Aum,g are also reported.
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##### Article: Charge radii and magnetic moments of odd-A 183-189 Pb isotopes
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ABSTRACT: Isotope shifts and hyperfine splitting parameters have been measured for the neutron-deficient odd-mass lead isotopes 183–189 Pb. The measurement was performed at the ISOLDE (CERN) online mass separator using the in-source resonance ionization spectroscopy technique. The nuclear root mean square charge radii r 2 and the electromagnetic moments μ and QS have been deduced. They follow the smooth trend of the heavier isotopes and indicate the absence of deformation.
European Physical Journal A 09/2009; 4162(3):315-321. DOI:10.1140/epja/i2009-10817-3 · 2.42 Impact Factor
• ##### Article: α decay of^{180,181} Pb
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ABSTRACT: A detailed α-decay study of the neutron-deficient isotope 181Pb has been performed in the complete fusion reaction 40Ca+144Sm→184Pb* at the velocity filter SHIP (GSI, Darmstadt). In comparison with the literature, more precise data have been deduced for the Iπ=(9/2-) ground state in this nucleus, which is presumably based on the neutron νh9/2 spherical orbital. Improved α-decay data were also measured for 180Pb.
Physical Review C 11/2009; 80(5). DOI:10.1103/PhysRevC.80.054322 · 3.88 Impact Factor