Modification of nuclear transitions in stellar plasma by electronic processes: K-isomers in 176Lu and 180Ta under s-process conditions

Abstract

The influence of the stellar plasma on the production and destruction of K-isomers is studied for the examples 176Lu and 180Ta. Individual electromagnetic transitions are enhanced predominantly by nuclear excitation by electron capture, whereas the other mechanisms of electron scattering and nuclear excitation by electron transition give only minor contributions. It is found that individual transitions can be enhanced significantly for low transition energies below 100 keV. Transitions with higher energies above 200 keV are practically not affected. Although one low-energy transition in 180Ta is enhanced by up to a factor of 10, the stellar transition rates from low-K to high-K states via so-called intermediate states in 176Lu and 180Ta do not change significantly under s-process conditions. The s-process nucleosynthesis of 176Lu and 180Ta remains essentially unchanged.

10 pages, 10 figures, Phys. Rev. C, accepted

References in corpus (6)

• s Process in low-mass Asymptotic Giant Branch Stars
• Survival of Nature's Rarest Isotope 180Ta under Stellar Conditions
• New estimate for the time-dependent thermal nucleosynthesis of ${}^{180}$Ta${}^m$
• Properties of the 5- state at 839 keV in 176Lu and the s-process branching at A = 176
• Relation between the 16O(alpha,gamma)20Ne reaction and its reverse 20Ne(gamma,alpha)16O reaction in stars and in the laboratory
• Thermal Equilibration of 176-Lu via K-Mixing

Cited by in corpus (4)

• Astronuclear Physics: a Tale of the Atomic Nuclei in the Skies
• 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
• Reanalysis of the (J = 5) state at 592 keV in 180Ta and its role in the neutrino-process nucleosynthesis of 180Ta in supernovae
• Coupling highly excited nuclei to the atomic shell in dense astrophysical plasmas