@misc{10481/95637,
year = {2024},
month = {7},
url = {https://hdl.handle.net/10481/95637},
abstract = {Asymptotic giant branch stars are responsible for the production of most of the heavy isotopes beyond Sr
observed in the solar system. Among them, isotopes shielded from the r-process contribution by their stable
isobars are defined as s-only nuclei. For a long time the abundance of 204Pb, the heaviest s-only isotope, has
been a topic of debate because state-of-the-art stellar models appeared to systematically underestimate its
solar abundance. Besides the impact of uncertainties from stellar models and galactic chemical evolution
simulations, this discrepancy was further obscured by rather divergent theoretical estimates for the neutron
capture cross section of its radioactive precursor in the neutron-capture flow, 204Tl (t1=2
¼ 3.78 yr), and by
the lack of experimental data on this reaction. We present the first ever neutron capture measurement on
204Tl, conducted at the CERN neutron time-of-flight facility n_TOF, employing a sample of only 9 mg of
204Tl produced at the Institute Laue Langevin high flux reactor. By complementing our new results with
semiempirical calculations we obtained, at the s-process temperatures of kT ≈ 8 keV and kT ≈ 30 keV,
Maxwellian-averaged cross sections (MACS) of 580(168) mb and 260(90) mb, respectively. These figures
are about 3% lower and 20% higher than the corresponding values widely used in astrophysical
calculations, which were based only on theoretical calculations. By using the new 204Tl MACS, the
uncertainty arising from the 204Tlðn; γÞ cross section on the s-process abundance of 204Pb has been reduced
from ∼30% down to þ8%= − 6%, and the s-process calculations are in agreement with the latest solar
system abundance of 204Pb reported by K. Lodders in 2021.},
organization = {Argos Scholarship of the
Universtitat Polit`ecnica de Catalunya (UPC)},
organization = {Consejo de Seguridad Nuclear (CSN)},
organization = {Spanish
Government Ministries MINECO (projects FPA2014-
52823-C2-1/2-P and FPA2017-83946-C2-1/2-P) and
MCIU (projects PID2019–104714 GB-C21 and
PID2022-138297NB-C21)},
organization = {C FP7 projects
NeutAndalus (Grant No. 334315) and CHANDA (Grant
No. 605203)},
organization = {n_TOF Collaboration and the Institut
de T`ecniques Energ`etiques (INTE) of the UPC. A. C. H.},
organization = {Margarita Salas grant by
the UPC (Agreement CG/2021/03/23) funded by the
Ministerio de Universidades (Order UNI/551/2021) and
by the European Union NextGenerationEU/PRTR},
organization = {ERC Consolidator
Grant HYMNS, Grant Agreement No. 681740.},
organization = {NuGrid from STFC
(through the University of Hull’s Consolidated Grant
No. ST/R000840/1), from the ERC Consolidator Grant (Hungary) funding scheme (Project RADIOSTAR, G. A.
n. 724560), from the ChETEC COST Action (CA16117),
supported by the European Cooperation in Science and
Technology},
organization = {IReNA network supported by NSF
AccelNet, from the National Science Foundation (NSF,
USA) under Grant No. PHY-1430152 (JINA Center for the
Evolution of the Elements)},
organization = {NKFI via K-project
138031},
organization = {Lendület Program LP2023-10 of the
Hungarian Academy of Sciences and from the European
Union’s Horizon 2020 research and innovation programme
(ChETEC-INFRA—Project No. 101008324)},
organization = {Science and Technology Facilities
Council UK (ST/M006085/1)},
organization = {European Research
Council ERC-2015-STG No. 677497},
publisher = {American Physical Society},
title = {Shedding Light on the Origin of 204Pb, the Heaviest s-Process–Only Isotope in the Solar System},
doi = {10.1103/PhysRevLett.133.052702},
author = {Casanovas-Hoste, A. and Porras Sánchez, José Ignacio and Praena Rodríguez, Antonio Javier and n_TOF Collaboration, /},
}