Cross-Section Measurements of the 86Kr(g,n) Reaction to Probe the s-Process Branching at 85Kr

Abstract

We have carried out photodisintegration cross-section measurements on 86Kr using monoenergetic photon beams ranging from the neutron separation energy, S_n = 9.86 MeV, to 13 MeV. We combine our experimental 86Kr(g,n)85Kr cross section with results from our recent 86Kr(g,g') measurement below the neutron separation energy to obtain the complete nuclear dipole response of 86Kr. The new experimental information is used to predict the neutron capture cross section of 85Kr, an important branching point nucleus on the abundance flow path during s-process nucleosynthesis. Our new and more precise 85Kr(n,g)86Kr cross section allows to produce more precise predictions of the 86Kr abundance from s-process models. In particular, we find that the models of the s-process in asymptotic giant branch stars of mass < 1.5 Msun, where the 13C neutron source burns convectively rather than radiatively, represent a possible solution for the highest 86Kr/82Kr ratios observed in meteoritic stardust SiC grains.

5 pages, 5 figure, accepted for publication on Physical Review Letters

References in corpus (5)

• Evolution, nucleosynthesis and yields of low mass AGB stars at different metallicities (II): the FRUITY database
• The s process in asymptotic giant branch stars of low metallicity and the composition of carbon-enhanced metal-poor stars
• s-process branching at 185W revised
• Is the Sulphur Anomaly in Planetary Nebulae Caused by the s-Process?
• Investigation of photoneutron reactions close to and above the neutron emission threshold in the rare earth region

Cited by in corpus (13)

• The Branchings of the Main s-process: Their Sensitivity to alpha-induced Reactions on 13C and 22Ne and to the Uncertainties of the Nuclear Network
• Novel Techniques for Constraining Neutron-Capture Rates Relevant for r-Process Heavy-Element Nucleosynthesis
• NuGrid stellar data set - III. Updated low-mass AGB models and s-process nucleosynthesis with metallicities Z=0.01, Z=0.02 and Z=0.03
• The importance of the 13C(alpha,n)16O reaction in Asymptotic Giant Branch stars
• Pygmy and core polarization dipole modes in ${}^{206}$Pb: connecting nuclear structure to stellar nucleosynthesis
• Astromers in the radioactive decay of r-process nuclei
• Partial mixing and the formation of 13C pockets in AGB stars: effects on the s-process elements
• Sensitivity study for s process nucleosynthesis in AGB stars
• Photoneutron reaction cross section measurements on 94Mo and 90Zr relevant to the p-process nucleosynthesis
• Compilation of isomeric ratios of light particle induced nuclear reactions
• New Modes of Nuclear Excitations
• Stellar yields and abundances: new directions from planetary nebulae
• Nuclear level densities and $\gamma$-ray strength functions of ${}^{87}\mathrm{Kr}$ -- First application of the Oslo Method in inverse kinematics