Nuclei in the Cosmos (NIC XVII)

Measurement of the low energy resonances in 22Ne(a,g) and 22Ne(a,n) reaction

18 Sept 2023, 15:00

15m

Oral Underground nuclear astrophysics Underground nuclear astrophysics

Speaker

Ms Shahina SHAHINA (University of Notre Dame)

Description

The interplay and correlation between the ${}^{22}$Ne$(\alpha ,\gamma {)}^{26}$Mg and the competing ${}^{22}$Ne$(\alpha ,n{)}^{25}$Mg reaction determines the efficiency of the ${}^{22}$Ne$(\alpha ,n{)}^{25}$Mg reaction as a neutron source for the weak $s$-process. In both cases, the reaction rates are dominated by the strength of the $\alpha$ cluster resonance at 830 keV. This plays a particularly important role in determining the strength of the neutron flux for weak and main s-process environments. We performed the measurement of the 830 keV resonance in ${}^{22}$Ne$(\alpha ,\gamma {)}^{26}$Mg at the Sanford Underground Research Facility using a $\gamma$-summing detector. We confirmed the previous studies of the resonance strength and obtained a strength of $\omega \gamma$ = 35 $\pm$ 4 $\mu$eV, however the strength of the corresponding resonance in the ${}^{22}$Ne$(\alpha ,n{)}^{25}$Mg still carries large uncertainties. In a new and independent study performed at Notre Dame using a stilbene crystal detector, we confirmed previous results and demonstrate that the resonance strength in the competing ${}^{22}$Ne$(\alpha ,n{)}^{25}$Mg reaction channel is significantly higher.

Presentation materials

5. NIC_2023_Shahina.pdf