Decay properties of 22Ne + α resonances and their impact on s-process nucleosynthesis
Abstract
The astrophysical s-process is one of the two main processes forming elements heavier than iron. A key outstanding uncertainty surrounding s-process nucleosynthesis is the neutron flux generated by the reaction during the He-core and C-shell burning phases of massive stars. This reaction, as well as the competing reaction, is not well constrained in the important temperature regime from ~0.2–0.4 GK, owing to uncertainties in the nuclear properties of resonances lying within the Gamow window. To address these uncertainties, we have performed a new measurement of the reaction in inverse kinematics, detecting the outgoing deuterons and recoils in coincidence. We have established a new decay branching ratio of for the key MeV resonance in , which results in a new strength for this resonance of when combined with the well-established strength of this resonance. We have also determined new upper limits on the α partial widths of neutron-unbound resonances at , 11.163, 11.169, and 11.171 MeV. Monte-Carlo calculations of the stellar and rates, which incorporate these results, indicate that both rates are substantially lower than previously thought in the temperature range from ~0.2–0.4 GK.
- Publication Date:
- Research Org.:
- Texas A & M Univ., College Station, TX (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA)
- OSTI Identifier:
- 1595170
- Alternate Identifier(s):
- OSTI ID: 1801153
- Grant/Contract Number:
- FG02-93ER4077; NA0003841
- Resource Type:
- Published Article
- Journal Name:
- Physics Letters B
- Additional Journal Information:
- Journal Name: Physics Letters B Journal Volume: 802 Journal Issue: C; Journal ID: ISSN 0370-2693
- Publisher:
- Elsevier
- Country of Publication:
- Netherlands
- Language:
- English
- Subject:
- 79 ASTRONOMY AND ASTROPHYSICS; Astronomy & Astrophysics; Physics
Citation Formats
Ota, S., Christian, G., Lotay, G., Catford, W. N., Bennett, E. A., Dede, S., Doherty, D. T., Hallam, S., Hooker, J., Hunt, C., Jayatissa, H., Matta, A., Moukaddam, M., Rogachev, G. V., Saastamoinen, A., Tostevin, J. A., Upadhyayula, S., and Wilkinson, R. Decay properties of 22Ne + α resonances and their impact on s-process nucleosynthesis. Netherlands: N. p., 2020.
Web. doi:10.1016/j.physletb.2020.135256.
Ota, S., Christian, G., Lotay, G., Catford, W. N., Bennett, E. A., Dede, S., Doherty, D. T., Hallam, S., Hooker, J., Hunt, C., Jayatissa, H., Matta, A., Moukaddam, M., Rogachev, G. V., Saastamoinen, A., Tostevin, J. A., Upadhyayula, S., & Wilkinson, R. Decay properties of 22Ne + α resonances and their impact on s-process nucleosynthesis. Netherlands. https://doi.org/10.1016/j.physletb.2020.135256
Ota, S., Christian, G., Lotay, G., Catford, W. N., Bennett, E. A., Dede, S., Doherty, D. T., Hallam, S., Hooker, J., Hunt, C., Jayatissa, H., Matta, A., Moukaddam, M., Rogachev, G. V., Saastamoinen, A., Tostevin, J. A., Upadhyayula, S., and Wilkinson, R. Sun .
"Decay properties of 22Ne + α resonances and their impact on s-process nucleosynthesis". Netherlands. https://doi.org/10.1016/j.physletb.2020.135256.
@article{osti_1595170,
title = {Decay properties of 22Ne + α resonances and their impact on s-process nucleosynthesis},
author = {Ota, S. and Christian, G. and Lotay, G. and Catford, W. N. and Bennett, E. A. and Dede, S. and Doherty, D. T. and Hallam, S. and Hooker, J. and Hunt, C. and Jayatissa, H. and Matta, A. and Moukaddam, M. and Rogachev, G. V. and Saastamoinen, A. and Tostevin, J. A. and Upadhyayula, S. and Wilkinson, R.},
abstractNote = {The astrophysical s-process is one of the two main processes forming elements heavier than iron. A key outstanding uncertainty surrounding s-process nucleosynthesis is the neutron flux generated by the reaction during the He-core and C-shell burning phases of massive stars. This reaction, as well as the competing reaction, is not well constrained in the important temperature regime from ~0.2–0.4 GK, owing to uncertainties in the nuclear properties of resonances lying within the Gamow window. To address these uncertainties, we have performed a new measurement of the reaction in inverse kinematics, detecting the outgoing deuterons and recoils in coincidence. We have established a new decay branching ratio of for the key MeV resonance in , which results in a new strength for this resonance of when combined with the well-established strength of this resonance. We have also determined new upper limits on the α partial widths of neutron-unbound resonances at , 11.163, 11.169, and 11.171 MeV. Monte-Carlo calculations of the stellar and rates, which incorporate these results, indicate that both rates are substantially lower than previously thought in the temperature range from ~0.2–0.4 GK.},
doi = {10.1016/j.physletb.2020.135256},
journal = {Physics Letters B},
number = C,
volume = 802,
place = {Netherlands},
year = {2020},
month = {3}
}
https://doi.org/10.1016/j.physletb.2020.135256
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