A direct measurement of the 17O(a,?)21Ne reaction in inverse kinematics and its impact on heavy element production

Taggart, M.P.; Akers, C.; Laird, A.M.; Hager, U.; Ruiz, C.; Hutcheon, D.A.; Bentley, M.A.; Brown, J.R.; Buchmann, L.; Chen, A.A.; Chen, J.; Chipps, K.A.; Choplin, A.; D'Auria, J.M.; Davids, B.; Davis, C.; Aa. Diget, C.; Erikson, L.; Fallis, J.; Fox, S.P.; Frischknecht, U.; Fulton, B.R.; Galinski, N.; Greife, U.; Hirschi, R.; Howell, D.; Martin, L.; Mountford, D.; Murphy, A.St.J.; Ottewell, D.; Pignatari, M.; Reeve, S.; Ruprecht, G.; Sjue, S.; Veloce, L.; Williams, M.

doi:10.1016/j.physletb.2019.134894

A direct measurement of the 17O(a,?)21Ne reaction in inverse kinematics and its impact on heavy element production

Taggart, M.P.; Akers, C.; Laird, A.M.; Hager, U.; Ruiz, C.; Hutcheon, D.A.; Bentley, M.A.; Brown, J.R.; Buchmann, L.; Chen, A.A.; Chen, J.; Chipps, K.A.; Choplin, A.; D'Auria, J.M.; Davids, B.; Davis, C.; Aa. Diget, C.; Erikson, L.; Fallis, J.; Fox, S.P.; Frischknecht, U.; Fulton, B.R.; Galinski, N.; Greife, U.; Hirschi, R.; Howell, D.; Martin, L.; Mountford, D.; Murphy, A.St.J.; Ottewell, D.; Pignatari, M.; Reeve, S.; Ruprecht, G.; Sjue, S.; Veloce, L.; Williams, M.

Authors

M.P. Taggart

C. Akers

A.M. Laird

U. Hager

C. Ruiz

D.A. Hutcheon

M.A. Bentley

J.R. Brown

L. Buchmann

A.A. Chen

J. Chen

K.A. Chipps

A. Choplin

J.M. D'Auria

B. Davids

C. Davis

C. Aa. Diget

L. Erikson

J. Fallis

S.P. Fox

U. Frischknecht

B.R. Fulton

N. Galinski

U. Greife

Raphael Hirschi r.hirschi@keele.ac.uk

D. Howell

L. Martin

D. Mountford

A.St.J. Murphy

D. Ottewell

M. Pignatari

S. Reeve

G. Ruprecht

S. Sjue

L. Veloce

M. Williams

Abstract

During the slow neutron capture process in massive stars, reactions on light elements can both produce and absorb neutrons thereby influencing the final heavy element abundances. At low metallicities, the high neutron capture rate of 16O can inhibit s-process nucleosynthesis unless the neutrons are recycled via the 17O(a,n)20Ne reaction. The efficiency of this neutron recycling is determined by competition between the 17O(a,n)20Ne and 17O(a,?)21Ne reactions. While some experimental data are available on the former reaction, no data exist for the radiative capture channel at the relevant astrophysical energies. The 17O(a,?)21Ne reaction has been studied directly using the DRAGON recoil separator at the TRIUMF Laboratory. The reaction cross section has been determined at energies between 0.6 and 1.6 MeV Ecm, reaching into the Gamow window for core helium burning for the first time. Resonance strengths for resonances at 0.63, 0.721, 0.81 and 1.122 MeV Ecm have been extracted. The experimentally based reaction rate calculated represents a lower limit, but suggests that significant s-process nucleosynthesis occurs in low metallicity massive stars.

Journal Article Type	Article
Acceptance Date	Aug 23, 2019
Online Publication Date	Aug 28, 2019
Publication Date	Nov 10, 2019
Publicly Available Date	May 26, 2023
Journal	Physics Letters B
Print ISSN	0370-2693
Publisher	Elsevier
Peer Reviewed	Peer Reviewed
Volume	798
Issue	10
Article Number	134894
DOI	https://doi.org/10.1016/j.physletb.2019.134894
Publisher URL	https://doi.org/10.1016/j.physletb.2019.134894