Decay of the key 92-keV resonance in the 25Mg(p,γ) reaction to the ground and isomeric states of the cosmic γ-ray emitter 26Al

A. Kankainen; P.J. Woods; D.T. Doherty; H.M. Albers; M. Albers; A.D. Ayangeakaa; M.P. Carpenter; C.J. Chiara; J.L. Harker; R.V.F. Janssens; C. Lederer-Woods; D. Seweryniak; F. Strieder; S. Zhu

Physics Letters B (Feb 2021)

Decay of the key 92-keV resonance in the 25Mg(p,γ) reaction to the ground and isomeric states of the cosmic γ-ray emitter 26Al

A. Kankainen,
P.J. Woods,
D.T. Doherty,
H.M. Albers,
M. Albers,
A.D. Ayangeakaa,
M.P. Carpenter,
C.J. Chiara,
J.L. Harker,
R.V.F. Janssens,
C. Lederer-Woods,
D. Seweryniak,
F. Strieder,
S. Zhu

Affiliations

A. Kankainen: University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom; University of Jyvaskyla, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland; Corresponding author at: University of Jyvaskyla, P.O. Box 35, FI-40014 University of Jyvaskyla, Finland.
P.J. Woods: University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
D.T. Doherty: University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom; University of Surrey, Guildford GU2 7XH, United Kingdom
H.M. Albers: Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA
M. Albers: Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA
A.D. Ayangeakaa: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255, USA; Triangle Universities Nuclear Laboratory, Duke University, Durham, NC 27708-2308, USA
M.P. Carpenter: Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA
C.J. Chiara: Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA; Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
J.L. Harker: Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA; Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
R.V.F. Janssens: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255, USA; Triangle Universities Nuclear Laboratory, Duke University, Durham, NC 27708-2308, USA
C. Lederer-Woods: University of Edinburgh, Edinburgh EH9 3JZ, United Kingdom
D. Seweryniak: Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA
F. Strieder: South Dakota School of Mines & Technology, Department of Physics, Rapid City, SD 57701, USA
S. Zhu: Physics Division, Argonne National Laboratory, Argonne, IL 60439, USA; National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973, USA

Journal volume & issue: Vol. 813
p. 136033

Abstract

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The 92-keV resonance in the 25Mg(p,γ)26Al reaction plays a key role in the production of 26Al at astrophysical burning temperatures of ≈100 MK in the Mg-Al cycle. However, the state can decay to feed either the ground, 26gAl, or isomeric state, 26mAl. It is the ground state that is critical as the source of cosmic γ rays. It is therefore important to precisely determine the ground-state branching fraction f0 of this resonance. Here we report on the identification of four γ-ray transitions from the 92-keV resonance, and determine the spin of the state and its ground-state branching fraction f0=0.52(2)stat(6)syst. The f0 value is the most precise reported to date, and at the lower end of the range of previously adopted values, implying a lower production rate of 26gAl and its cosmic 1809-keV γ rays.

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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