Strength measurement of the $E_{\hat{I}}{\pm }^{lab}$ = 830 keV resonance in ${}^{22}\mathrm{Ne}(\hat{\mathrm{I}}\pm ,\mathrm{n}{)}^{25}\mathrm{Mg}$ reaction using a stilbene detector

Abstract

The interplay between the ${}^{22}$Ne$(\hat{I}\pm ,{\hat{I}}^3{)}^{26}$Mg and the competing ${}^{22}$Ne$(\hat{I}\pm ,n{)}^{25}$Mg reactions determines the efficiency of the latter as a neutron source at the temperatures of stellar helium burning. In both cases, the rates are dominated by the $\hat{I}\pm$-cluster resonance at 830 keV. This resonance plays a particularly important role in determining the strength of the neutron flux for both the weak and main $s$-process as well as the $n$-process. Recent experimental studies based on transfer reactions suggest that the neutron and ${\hat{I}}^3$-ray strengths for this resonance are approximately equal. In this study, the ${}^{22}$Ne$(\hat{I}\pm ,n{)}^{25}$Mg resonance strength has been remeasured and found to be similar to the previous direct studies. This reinforces an 830 keV resonance strength that is approximately a factor of three larger for the ${}^{22}$Ne$(\hat{I}\pm ,n{)}^{25}$Mg reaction than for the ${}^{22}$Ne$(\hat{I}\pm ,{\hat{I}}^3{)}^{26}$Mg reaction.