Proton-unbound states in AI 24 relevant for the mg 23 (p,γ) reaction in novae

No Thumbnail Available

Date

2024

Journal Title

Journal ISSN

Volume Title

Publisher

American Physical Society

Abstract

Background: The nucleosynthesis of several proton-rich nuclei is determined by radiative proton-capture reactions on unstable nuclei in nova explosions. One such reaction is 23Mg(p, γ ) 24Al, which links the NeNa and MgAl cycles in oxygen-neon novae. Purpose: The purpose of our study is to extract 23Mg(p, γ ) resonance strengths from proton-unbound states in 24Al, produced via the 24Mg(3 He,t) reaction. Methods: A beam of 3 He2+ ions at 50.7 MeV is used to produce the states of interest in 24Al. Proton-triton angular correlations are measured with a K = 600 QDD magnetic spectrometer and a silicon detector array, located at iThemba LABS, South Africa. Results: We measure the excitation energies of the four lowest proton-unbound states in 24Al and place lower limits on p/ values for these four states. Together with shell-model calculations of partial γ widths, the experimental data are also used to determine resonance strengths for the four lowest 23Mg(p, γ ) 24Al resonances. Conclusions: The energy of the dominant first 23Mg(p, γ ) resonance is determined to be Er = 478 ± 4 keV, with a resonance strength of ωγ = 19 ± 9 meV.

Description

Keywords

Proton emission, Charge-exchange reactions, Nuclear reaction rates, Resonance reactions, Research Areas Charge-exchange reactionsNuclear astrophysicsNuclear reaction ratesNucleosynthesis in explosive environments

Citation

Vyfers, E.C., Pesudo, V., Triambak, S., Adsley, P., Brown, B.A., Jivan, H., Kamil, M., Marin-Lambarri, D.J., Neveling, R., Ondze, J.C. and Papka, P., 2023. Study of proton-unbound states in $^{24}{\rm Al} $ relevant for the $^{23}{\rm Mg}(p,\gamma) $ reaction in novae. arXiv preprint arXiv:2311.15935.