Shedding Light on the Origin of ²⁰⁴Pb, the Heaviest <i>s</i>-Process-Only Isotope in the Solar System

Autor(en)

, A. Casanovas-Hoste, C. Domingo-Pardo, J. Lerendegui-Marco, C. Guerrero, A. Tarifeño-Saldivia, M. Krtička, M. Pignatari, F. Calviño, D. Schumann, S. Heinitz, R. Dressler, U. Köster, O. Aberle, J. Andrzejewski, L. Audouin, V. Bécares, M. Bacak, J. Balibrea-Correa, M. Barbagallo, S. Barros, F. Bečvář, C. Beinrucker, E. Berthoumieux, J. Billowes, D. Bosnar, M. Brugger, M. Caamaño, M. Calviani, D. Cano-Ott, R. Cardella, D. M. Castelluccio, F. Cerutti, Y. H. Chen, E. Chiaveri, N. Colonna, G. Cortés, M. A. Cortés-Giraldo, L. Cosentino, L. A. Damone, M. Diakaki, E. Dupont, I. Durán, B. Fernández-Domínguez, A. Ferrari, P. Ferreira, P. Finocchiaro, V. Furman, M. Mirea, A. Pavlik, S. Schmidt

Abstrakt

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 ^{204}Pb, 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, ^{204}Tl (t_{1/2}=3.78  yr), and by the lack of experimental data on this reaction. We present the first ever neutron capture measurement on ^{204}Tl, conducted at the CERN neutron time-of-flight facility n_TOF, employing a sample of only 9 mg of ^{204}Tl 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 ^{204}Tl MACS, the uncertainty arising from the ^{204}Tl(n,γ) cross section on the s-process abundance of ^{204}Pb has been reduced from ∼30% down to +8%/-6%, and the s-process calculations are in agreement with the latest solar system abundance of ^{204}Pb reported by K. Lodders in 2021.

Organisation(en)

Isotopenphysik

Externe Organisation(en)

Universitat Politècnica de Catalunya, Universitat de València, European Organization for Nuclear Research (CERN), Universidad de Sevilla, Charles University Prague, MTA Társadalomtudományi Kutatóközpont, Magyar Tudományos Akadémia, University of Hull, Grid Collaboration, Paul Scherrer Institute, Institut Laue-Langevin (ILL), University of Lodz, Université Paris Saclay, Centro de Investigaciones Energeticas Medioambientales y Tecnológica, Technische Universität Wien, Istituto Nazionale di Fisica Nucleare (INFN), Roma, EURATOM Association, Johann Wolfgang Goethe-Universität Frankfurt am Main, University of Manchester, University of Zagreb, Universidade de Santiago de Compostela (USC), Agenzia nazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile, Università degli Studi di Bari Aldo Moro, Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering

Journal

Physical review letters

Band

133

Anzahl der Seiten

8

ISSN

0031-9007

DOI

https://doi.org/10.1103/PhysRevLett.133.052702

Publikationsdatum

08-2024

Peer-reviewed

Ja

ÖFOS 2012

103014 Kernphysik

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e598acfd-923e-4655-bdc1-f27c8181789e