Direct measurement of the low energy resonances in ${}^{22}\mathrm{Ne}(\alpha ,\gamma {)}^{26}\mathrm{Mg}$ reaction

Abstract

The ${}^{22}\mathrm{Ne}(\alpha ,\gamma {)}^{26}\mathrm{Mg}$ is an important reaction in stellar helium burning environments as it competes directly with one of the main neutron sources for the s-process, the ${}^{22}\mathrm{Ne}(\alpha ,\mathrm{n}{)}^{25}\mathrm{Mg}$ reaction. The reaction rate of the ${}^{22}\mathrm{Ne}(\alpha ,\gamma {)}^{26}\mathrm{Mg}$ is dominated by the low energy resonances at $E_{\alpha }^{lab}$ = 650 and 830 keV respectively. The $E_{\alpha }^{lab}$ = 830 keV resonance has been measured previously, but there are some uncertainties in the previous measurements. We confirmed the measurement of the $E_{\alpha }^{lab}$ = 830 keV resonance using implanted ${}^{22}$Ne targets. We obtained a resonance strength of $\omega \gamma$ = 35 $\pm$ 4 $\mu eV$, and provide a weighted average of the present and previous measurements of $\omega \gamma$ = 35 $\pm$ 2 $\mu eV$ with reduced uncertainties compared to previous studies. We also attempted to measure the strength of the predicted resonance at $E_{\alpha }^{lab}$ = 650 keV directly for the first time and found an upper limit of $\omega \gamma$ $<0.15$ $\mu eV$ for the strength of this resonance. In addition, we also studied the $E_P^{lab}$= 851 keV resonance in ${}^{22}\mathrm{Ne}(\mathrm{p},\gamma {)}^{23}\mathrm{Na}$, and obtained a resonance strength of $\omega \gamma$ = 9.2 $\pm$ 0.7 eV with significantly lower uncertainties compared to previous measurements.

10 pages, 6 figures

References in corpus (2)

• Constraining the ${}^{22}$Ne($\alpha$,$\gamma$)${}^{26}$Mg and ${}^{22}$Ne($\alpha$,n)${}^{25}$Mg reaction rates using sub-Coulomb $\alpha$-transfer reactions
• Decay properties of ${}^{22}\mathrm{Ne}+\alpha$ resonances and their impact on $s$-process nucleosynthesis

Cited by in corpus (7)

• The s Process and Beyond
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• First direct limit on the 334 keV resonance strength in the ${}^{22}$Ne(α,γ)${}^{26}$Mg reaction
• The ${}^{22}$Ne($\alpha$,n)${}^{25}$Mg reaction -- state of the art, astrophysics, and perspectives
• Strength measurement of the $E_{\alpha }^{lab}$ = 830 keV resonance in ${}^{22}\mathrm{Ne}(\alpha ,\mathrm{n}{)}^{25}\mathrm{Mg}$ reaction using a stilbene detector
• The 2025 Evaluation of Experimental Thermonuclear Reaction Rates (ETR25)
• Impact of the latest 22Ne+α reaction rates on nucleosynthesis in massive stars and galactic chemical evolution