Cross-Section Measurements of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mmultiscripts><mml:mi>Kr</mml:mi><mml:mprescripts /><mml:none /><mml:mn>86</mml:mn></mml:mmultiscripts><mml:mo stretchy="false">(</mml:mo><mml:mi>γ</mml:mi><mml:mo>,</mml:mo><mml:mi>n</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math>Reaction to Probe the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>s</mml:mi></mml:math>-Process Branching at<mml:math xmlns:

Raut, R.; Tonchev, A. P.; Rusev, G.; Tornow, W.; Iliadis, Christian; Lugaro, Maria; Buntain, Joelene; Goriely, Stéphane; Kelley, J. H.; Schwengner, R.; Banu, A.; Tsoneva, N.

doi:10.1103/physrevlett.111.112501

Cited by 59 publications

(36 citation statements)

References 34 publications

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“…This trend follows that of the neutron exposure in the interpulse (Table 4). The enrichments achieved are not enough to explain the typical observation for AGB stars of roughly solar metallcity that [Ba/Fe]∼1, hence, this model may be relevant only for specific applications, e.g., the production of 86 Kr (Raut et al 2013) or, potentially, the composition of Sakurai's Object, as an alternative to the proton-ingestion episode (Herwig et al 2011). …”

Section: Comparison Of the Results From Setmentioning

confidence: 99%

Partial mixing and the formation of 13C pockets in AGB stars: effects on the s-process elements

Buntain

Doherty

Lugaro

et al. 2017

Monthly Notices of the Royal Astronomical Society

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The production of the elements heavier than iron via slow neutron captures (the s process) is a main feature of the contribution of asymptotic giant branch (AGB) stars of low mass (< 5 Msun) to the chemistry of the cosmos. However, our understanding of the main neutron source, the 13 C(α,n) 16 O reaction, is still incomplete. It is commonly assumed that in AGB stars mixing beyond convective borders drives the formation of 13 C pockets. However, there is no agreement on the nature of such mixing and free parameters are present. By means of a parametric model we investigate the impact of different mixing functions on the final s-process abundances in low-mass AGB models. Typically, changing the shape of the mixing function or the mass extent of the region affected by the mixing produce the same results. Variations in the relative abundance distribution of the three s-process peaks (Sr, Ba, and Pb) are generally within +/-0.2 dex, similar to the observational error bars. We conclude that other stellar uncertainties -the effect of rotation and of overshoot into the C-O core -play a more important role than the details of the mixing function. The exception is at low metallicity, where the Pb abundance is significantly affected. In relation to the composition observed in stardust SiC grains from AGB stars, the models are relatively close to the data only when assuming the most extreme variation in the mixing profile.

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Section: Comparison Of the Results From Setmentioning

confidence: 99%

Partial mixing and the formation of 13C pockets in AGB stars: effects on the s-process elements

Buntain

Doherty

Lugaro

et al. 2017

Monthly Notices of the Royal Astronomical Society

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“…Inelastic scattering and photo-neutron reactions can be used to populate a nucleus of interest across a wide range of excitation energies, up to and beyond the neutron separation energy. Bremsstrahlung photons as well as quasi-monoenergetic γ-ray beams have been used for this purpose [21][22][23][24][25][26][27][28][29]. In a few experiments, neutrons emitted from the CN were detected and the (γ,n) cross sections were determined.…”

Section: Methods and Illustrative Examplementioning

confidence: 99%

“…In a few experiments, neutrons emitted from the CN were detected and the (γ,n) cross sections were determined. Hauser-Feshbach calculations of these photo-neutron reactions were carried out and comparisons with the data were utilized to determine the most appropriate combination of level densities and γ-ray strength functions [28,30]. These were subsequently employed to calculate the (n,γ) cross section of interest.…”

Section: Methods and Illustrative Examplementioning

confidence: 99%

Compound-nuclear reactions with unstable nuclei: Constraining theory through innovative experimental approaches

Escher

Tonchev

Burke

et al. 2016

EPJ Web of Conferences

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Abstract. Cross sections for compound-nuclear reactions involving unstable targets are important for many applications, but can often not be measured directly. Several indirect methods have recently been proposed to determine neutron capture cross sections for unstable isotopes. We consider three approaches that aim at constraining statistical calculations of capture cross sections with data obtained from the decay of the compound nucleus relevant to the desired reaction. Each method produces this compound nucleus in a different manner (via a light-ion reaction, a photon-induced reaction, or β-decay) and requires additional ingredients to yield the sought-after cross section. We give a brief outline of the approaches and employ preliminary results from recent measurements to illustrate the methods. We discuss the main advantages and challenges of each approach.

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“…The new recommended cross section is more than a factor of 2 higher over the whole astrophysical energy range than the previously recommended semi-empirical value. For 85 Kr no direct measurement exists but the new recommended value was inferred from a recent photoactivation measurement of 86 Kr [26]. The new cross section is about 35% higher than the previous semi-empirical value.…”

Section: Examples For Major Changesmentioning

confidence: 96%

The new KADoNiS v1.0 and its influence on the s-process

Dillmann¹

2015

Proceedings of XIII Nuclei in the Cosmos — PoS(NIC XIII)

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Cross-Section Measurements of theKr86(γ,n)Reaction to Probe thes-Process Branching at

Cited by 59 publications

References 34 publications

Partial mixing and the formation of 13C pockets in AGB stars: effects on the s-process elements

Partial mixing and the formation of 13C pockets in AGB stars: effects on the s-process elements

Compound-nuclear reactions with unstable nuclei: Constraining theory through innovative experimental approaches

The new KADoNiS v1.0 and its influence on the s-process

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