Lifetime measurement in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow /><mml:mrow><mml:mn>176</mml:mn></mml:mrow></mml:msup></mml:mrow><mml:mi mathvariant="normal">Lu</mml:mi></mml:math>and its astrophysical consequences

Doll, C.; Börner, H. G.; Jaag, S.; Käppeler, F.; Andrejtscheff, W.

doi:10.1103/physrevc.59.492

Cited by 42 publications

(40 citation statements)

References 16 publications

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“…This temperature dependence was later confirmed on the basis of comprehensive investigations of the level structure of 176 Lu ( Klay et al 1991a( Klay et al , 1991bDoll et al 1999). It turned out that such thermally induced transitions become effective at temperatures above 1:5 ; 10 8 K. Accordingly, ground state and isomer can be treated as separate species only at lower temperatures.…”

Section: Introductionmentioning

confidence: 79%

“…The half-life of 176 Lu was shown to decrease drastically at the temperatures reached during He shell burning in thermally pulsing low-mass AGB stars ( Klay et al 1991a;Doll et al 1999). Contrary to the situation at low excitation energy, where transitions between ground state and isomer are strictly forbidden by selection rules, interactions with the hot stellar photon bath lead to induced transitions to higher lying nuclear states, which can Wisshak et al (2006aWisshak et al ( , 2006b.…”

Section: Half-life Ofmentioning

confidence: 99%

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¹⁷⁶Lu/¹⁷⁶Hf: A Sensitive Test ofs‐Process Temperature and Neutron Density in AGB Stars

Heil

Winckler

Dababneh

et al. 2008

ApJ

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The s-process branching at A ¼ 176 has been analyzed on the basis of significantly improved experimental cross sections. This work reports on activation measurements of the partial (n; ) cross section of 176 Lu feeding the isomeric state in 176 Lu. In total, six irradiations were performed at the Karlsruhe 3.7 MV pulsed Van de Graaff accelerator, and the induced activities were measured with HPGe clover detectors. In combination with previous data, partial cross sections of 3185 AE 156 and 1153 AE 30 mbarn were deduced at kT ¼ 5:1 and 25 keV, respectively. With these results and a recent time-of-flight measurement of the total stellar (n; ) cross section, the isomeric ratio was found to be constant in the relevant thermal energy range of the main s-process component. Based on these new data, a comprehensive analysis of the branching at 176 Lu was carried out for testing the temperature and neutron density conditions during He shell flashes in thermally pulsing low-mass asymptotic giant branch stars. It was found that the long-standing problem of the mother/daughter ratio of the two s-only isotopes 176 Lu and 176 Hf could be solved, if the temperaturedependent -decay half-life of 176 Lu was considered with sufficient resolution over the temperature profile of the convective He shell flashes.

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Section: Introductionmentioning

confidence: 79%

Section: Half-life Ofmentioning

confidence: 99%

¹⁷⁶Lu/¹⁷⁶Hf: A Sensitive Test ofs‐Process Temperature and Neutron Density in AGB Stars

Heil

Winckler

Dababneh

et al. 2008

ApJ

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“…A similar analysis for the weak s-process component yields neutron densities of order (0.5-1.3) × 10 8 cm −3 (Walter et al, 1986a,b). We stress that a 10% determination of the neutron density requires the knowledge of the involved neutron capture cross sections with about 1% accuracy (Käppeler et al, 1998) Hf are shielded against r-process β-decays (adapted from Doll et al, 1999). FIG.…”

Section: A S-processmentioning

confidence: 99%

Nuclear weak-interaction processes in stars

2003

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Recent experimental data and progress in nuclear structure modeling have lead to improved descriptions of astrophysically important weak-interaction processes. The review discusses these advances and their applications to hydrostatic solar and stellar burning, to the slow and rapid neutron-capture processes, to neutrino nucleosynthesis, and to explosive hydrogen burning. Special emphasis is given to the weak-interaction processes associated with core-collapse supernovae. Despite some significant progress, important improvements are still warranted. Such improvements are expected to come from future radioactive ion-beam facilities.Comment: 45 pages, 33 figures, REVTeX 4, submitted to Rev. Mod. Phys., modified following referee's comment

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“…Important isomers are those in 176 Lu and in 180 Ta for example. The isomer in 176 Lu at 123 keV is the key for the interpretation of the mother/daughter ratio of the s-only isotopes 176 Lu and 176 Hf as an s-process thermometer for the He shell flashes in low mass AGB stars (Doll et al, 1999;Klay et al, 1991). At temperatures above about 150 MK the initial population probabilities of isomer (t 1/2 = 3.68 h) and ground state (t 1/2 = 37.5 Gyr) (Heil et al, 2008d;Wisshak et al, 2006b) are altered by a delicate interplay between neutron density and temperature, depending on subtle details in the nuclear structure of 176 Lu (Mohr et al, 2009).…”

Section: Activationsmentioning

confidence: 99%

Thesprocess: Nuclear physics, stellar models, and observations

et al. 2011

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Nucleosynthesis in the s process takes place in the He burning layers of low mass AGB stars and during the He and C burning phases of massive stars. The s process contributes about half of the element abundances between Cu and Bi in solar system material. Depending on stellar mass and metallicity the resulting s-abundance patterns exhibit characteristic features, which provide comprehensive information for our understanding of the stellar life cycle and for the chemical evolution of galaxies. The rapidly growing body of detailed abundance observations, in particular for AGB and post-AGB stars, for objects in binary systems, and for the very faint metal-poor population represents exciting challenges and constraints for stellar model calculations. Based on updated and improved nuclear physics data for the s-process reaction network, current models are aiming at ab initio solution for the stellar physics related to convection and mixing processes. Progress in the intimately related areas of observations, nuclear and atomic physics, and stellar modeling is reviewed and the corresponding interplay is illustrated by the general abundance patterns of the elements beyond iron and by the effect of sensitive branching points along the sprocess path. The strong variations of the s-process efficiency with metallicity bear also interesting consequences for Galactic chemical evolution.

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Lifetime measurement in176Luand its astrophysical consequences

Cited by 42 publications

References 16 publications

¹⁷⁶Lu/¹⁷⁶Hf: A Sensitive Test ofs‐Process Temperature and Neutron Density in AGB Stars

¹⁷⁶Lu/¹⁷⁶Hf: A Sensitive Test ofs‐Process Temperature and Neutron Density in AGB Stars

Nuclear weak-interaction processes in stars

Thesprocess: Nuclear physics, stellar models, and observations

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Lifetime measurement in176Luand its astrophysical consequences

Cited by 42 publications

References 16 publications

176Lu/176Hf: A Sensitive Test ofs‐Process Temperature and Neutron Density in AGB Stars

176Lu/176Hf: A Sensitive Test ofs‐Process Temperature and Neutron Density in AGB Stars

Nuclear weak-interaction processes in stars

Thesprocess: Nuclear physics, stellar models, and observations

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Product

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¹⁷⁶Lu/¹⁷⁶Hf: A Sensitive Test ofs‐Process Temperature and Neutron Density in AGB Stars

¹⁷⁶Lu/¹⁷⁶Hf: A Sensitive Test ofs‐Process Temperature and Neutron Density in AGB Stars