Related papers: $^{180}$Ta production in the classical s-process
The nucleosynthesis of nature's rarest isotope 180Ta depends sensitively on the temperature of the astrophysical environment because of depopulation of the long-living isomeric state via intermediate states to the short-living ground state…
We have made a new time-dependent calculation of the supernova production ratio of the long-lived isomeric state of $^{180}$Ta. Such a time-dependent solution is crucial for understanding the production and survival of this isotope. We…
We analyze the production and freeze-out of the isomer 180Tam in the neutrino-process. We consider the influence of a possible low-lying intermediate (J = 5) state at 592 keV using a transition width estimated from the measured half-life.…
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,…
Tantalum-180m is nature's rarest (quasi) stable isotope and its astrophysical origin is an open question. A possible production site of this isotope is the slow neutron capture process in Asymptotic Giant Branch stars, where it can be…
The neutron capture cross section of the unstable nucleus 185W has been derived from experimental photoactivation data of the inverse reaction 186W(gamma,n)185W. The new result of sigma = (687 +- 110) mbarn confirms the theoretically…
Current models of s-nucleosynthesis in massive stars ($M\sim15 M_{\odot}$ to $\sim 30 M_{\odot}$) are able to reproduce some main features of the abundance distributions of heavy isotopes in the solar system, at least in the $A\sim 60-90$…
The first detection of a $^{36}$S-bearing molecule in interstellar space is reported. The $J$=$2-1$ and $3-2$ transitions of C$^{36}$S have been observed toward eight Galactic molecular hot cores. From a comparison with other optically thin…
We present the first calculations to follow the evolution of all stable isotopes (and their abundant radioactive progenitors) in a finely zoned stellar model computed from the onset of central hydrogen burning through explosion as a Type II…
Context: It is well known that the so-called s-process is responsible for the production of neutron-rich trans-iron elements, that form the bulk of the "heavy nuclides" (i.e. nuclides more massive than the iron-group nuclei) in the…
The neutron capture cross section of the unstable s-process branching nucleus 185W has been derived from experimental data of the inverse 186W(g,n)185W photodisintegration taken with monochromatic photon beams from laser Compton scattering.…
The recently improved information on the stellar neutron capture cross sections of neutron magic nuclei at N = 82, and in particular for 142^Nd, turned out to represent a sensitive test for models of s-process nucleosynthesis. While these…
Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The ($n,\gamma$) cross section on $^{70}$Ge, which is…
De-excitation $\gamma $ rays associated with an isomeric state of $^{186}$Ta were investigated. The isomers were produced in multinucleon transfer reactions between a $^{136}$Xe beam and a natural W target, and were collected and separated…
$^{\rm {180m}}$Ta is the rarest naturally occurring quasi-stable isotope and the longest lived metastable state which is known. Its possible decay via the $\beta^-$ or the electron capture channel has never been observed. This article…
Within the framework of the isospin-dependent quantum molecular dynamics model along with the GEMINI model, the reaction of $^{86}$Kr+$^{181}$Ta at 80,120 and 160 MeV/nucleon and the reaction of $^{78}$Kr+$^{181}$Ta at 160 MeV/nucleon are…
We present a comprehensive study of s-process nucleosynthesis in 15, 20, 25, and 30 $\msun$ stellar models having solar-like initial composition. The stars are evolved up to ignition of central neon with a 659 species network coupled to the…
We study a new s-process path through an isomer of $^{186}$Re to improve a $^{187}$Re-$^{187}$Os nucleo-cosmochronometer. The nucleus $^{187}$Re is produced by this new path of $^{185}$Re(n,$\gamma$)$^{186}$Re$^m$(n,$\gamma$)$^{187}$Re. We…
We have calculated the stellar $\beta$-decay rate of the important s-process branching point ${}^{134}$Cs based on the state of the art shell model calculations. At typical $s$-process temperatures ($T\sim$ 0.2-0.3 GK), our new rate is one…
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…