Wed·Aug 17, 2022Wednesday·August 17, 2022

1. 01*

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

   S. Shahina🇺🇸 · J. Gorres · D. Robertson · M. Couder🇺🇸 · O. Gomez · A. Gula🇺🇸 · M. Hanhardt · T. Kadlecek · R. Kelmar · P. Scholz · A. Simon🇮🇱 · E. Stech · F. Strieder🇺🇸 · M. Wiescher🇺🇸

   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.

   nucl-exPRC(2022)·11 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.