Direct measurement of the low-energy resonances in 22Ne(α,γ)26Mg reaction

The  22 Ne  ⁢(𝛼,𝛾)⁢ 26 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 Ne  ⁢(𝛼,𝑛)⁢ 25 Mg   reaction. The reaction rate of the 22 Ne  ⁢(𝛼,𝛾)⁢ 26 Mg   is dominated by the low-energy resonances at 𝐸lab 𝛼=650 and 830 keV, respectively. The 𝐸lab 𝛼=830-keV resonance has been measured previously, but there are some uncertainties in the previous measurements. We confirmed the measurement of the 𝐸lab 𝛼=830-keV resonance using implanted  22 Ne   targets. We obtained a resonance strength of 𝜔⁢𝛾=35±4 𝜇⁢eV and provide a weighted average of the present and previous measurements of 𝜔⁢𝛾=35±2 𝜇⁢eV with reduced uncertainties compared to previous studies. We also attempted to measure the strength of the predicted resonance at 𝐸lab 𝛼=650 keV directly for the first time and found an upper limit of 𝜔⁢𝛾<0.15 𝜇⁢eV for the strength of this resonance. In addition, we also studied the 𝐸lab 𝑃=851-keV resonance in  22 Ne  ⁢(𝑝,𝛾)⁢ 23 Na   and obtained a resonance strength of 𝜔⁢𝛾=9.2±0.7 eV with significantly lower uncertainties compared to previous measurements.