Re-estimation of 180Ta nucleosynthesis in light of newly constrained reaction rates

K.L. Malatji; M. Wiedeking; S. Goriely; C.P. Brits; B.V. Kheswa; F.L. Bello Garrote; D.L. Bleuel; F. Giacoppo; A. Görgen; M. Guttormsen; K. Hadynska-Klek; T.W. Hagen; V.W. Ingeberg; M. Klintefjord; A.C. Larsen; P. Papka; T. Renstrøm; E. Sahin; S. Siem; L. Siess; G.M. Tveten; F. Zeiser

Physics Letters B (Apr 2019)

Re-estimation of 180Ta nucleosynthesis in light of newly constrained reaction rates

K.L. Malatji,
M. Wiedeking,
S. Goriely,
C.P. Brits,
B.V. Kheswa,
F.L. Bello Garrote,
D.L. Bleuel,
F. Giacoppo,
A. Görgen,
M. Guttormsen,
K. Hadynska-Klek,
T.W. Hagen,
V.W. Ingeberg,
M. Klintefjord,
A.C. Larsen,
P. Papka,
T. Renstrøm,
E. Sahin,
S. Siem,
L. Siess,
G.M. Tveten,
F. Zeiser

Affiliations

K.L. Malatji: iThemba LABS, P.O. Box 722, 7129 Somerset West, South Africa; Physics Department, University of Stellenbosch, Matieland, 7602, South Africa; Corresponding author at: iThemba LABS, P.O. Box 722, 7129 Somerset West, South Africa.
M. Wiedeking: iThemba LABS, P.O. Box 722, 7129 Somerset West, South Africa
S. Goriely: Institut d'Astronomie et d'Astrophysique, Université Libre de Bruxelles, CP 226, B-1050 Brussels, Belgium
C.P. Brits: iThemba LABS, P.O. Box 722, 7129 Somerset West, South Africa; Physics Department, University of Stellenbosch, Matieland, 7602, South Africa
B.V. Kheswa: iThemba LABS, P.O. Box 722, 7129 Somerset West, South Africa; Department of Applied Physics and Engineering Mathematics, University of Johannesburg, Johannesburg, 2028, South Africa
F.L. Bello Garrote: Department of Physics, University of Oslo, N-0316 Oslo, Norway
D.L. Bleuel: Lawrence Livermore National Laboratory, Livermore, CA 94551, USA
F. Giacoppo: Department of Physics, University of Oslo, N-0316 Oslo, Norway; Helmholtz Institute Mainz, 55099 Mainz, Germany; GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291 Darmstadt, Germany
A. Görgen: Department of Physics, University of Oslo, N-0316 Oslo, Norway
M. Guttormsen: Department of Physics, University of Oslo, N-0316 Oslo, Norway
K. Hadynska-Klek: Department of Physics, University of Oslo, N-0316 Oslo, Norway
T.W. Hagen: Department of Physics, University of Oslo, N-0316 Oslo, Norway
V.W. Ingeberg: Department of Physics, University of Oslo, N-0316 Oslo, Norway
M. Klintefjord: Department of Physics, University of Oslo, N-0316 Oslo, Norway
A.C. Larsen: Department of Physics, University of Oslo, N-0316 Oslo, Norway
P. Papka: iThemba LABS, P.O. Box 722, 7129 Somerset West, South Africa; Physics Department, University of Stellenbosch, Matieland, 7602, South Africa
T. Renstrøm: Department of Physics, University of Oslo, N-0316 Oslo, Norway
E. Sahin: Department of Physics, University of Oslo, N-0316 Oslo, Norway
S. Siem: Department of Physics, University of Oslo, N-0316 Oslo, Norway
L. Siess: Institut d'Astronomie et d'Astrophysique, Université Libre de Bruxelles, CP 226, B-1050 Brussels, Belgium
G.M. Tveten: Department of Physics, University of Oslo, N-0316 Oslo, Norway
F. Zeiser: Department of Physics, University of Oslo, N-0316 Oslo, Norway

Journal volume & issue: Vol. 791
pp. 403 – 408

Abstract

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Recent measurements of the nuclear level densities and γ-ray strength functions below the neutron thresholds in 180,181,182Ta are used as input in the nuclear reaction code TALYS. These experimental average quantities are utilized in the calculations of the 179,180,181Ta radiative neutron capture cross sections. From the latter, astrophysical Maxwellian-averaged (n,γ) cross sections (MACS) and reaction rates are extracted, which in turn are used in large astrophysical network calculations to probe the production mechanism of 180Ta. These calculations are performed for two scenarios, the s-process production of 180,181Ta in Asymptotic Giant Branch (AGB) stars and the p-process nucleosynthesis of Tam180 in Type-II supernovae. Based on the results from this work, the s-process in stellar evolution is considered negligible in the production of Tam180 whereas 181Ta is partially produced by AGB stars. The new measurements strongly constrain the production and destruction rates of Tam180 at p-process temperatures and confirm significant production of nature's rarest stable isotope Tam180 by the p-process. Keywords: Nuclear level density, γ-ray strength function, (n,γ) cross sections, Maxwellian-averaged cross sections, Nucleosynthesis

Published in Physics Letters B

ISSN: 0370-2693 (Print); 1873-2445 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Physics
Website: http://www.journals.elsevier.com/physics-letters-b/

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