Low-energy resonances in14N(α,γ)18Fand their astrophysical implications

The strengths of low-energy resonances in ${}^{14}\mathrm{N}(\alpha ,\gamma {)}^{18}\mathrm{F}$ at 573 keV and 1136 keV have been measured using an activation method. In addition, their relative strength and the energy of the lower resonance have been determined in a prompt $\gamma$-ray experiment. The results of these measurements are used to reevaluate the stellar reaction rate of ${}^{14}\mathrm{N}(\alpha ,\gamma {)}^{18}\mathrm{F}.$ The present reaction rate at temperatures of astrophysical interest is a factor of 2 smaller than previously reported.