Measurement of theO17(p,α)N14Cross Section at Stellar Energies

The cross section for the astrophysically important ${}_{}{}^{17}{}_{}{}^{}O(p,\alpha ){}_{}{}^{14}{}_{}{}^{}N$ reaction was measured at proton energies of 75 and 65 keV. Thick, high-purity ${\mathrm{Ta}}_2{O}_5$ targets (77% enriched ${}_{}{}^{17}{}_{}{}^{}O$) and large-area detectors were used with beam currents of 0.45 mA. Backgrounds were measured using ${\mathrm{Ta}}_2{O}_5$ targets of natural isotopic composition. The expected resonance at $E_p=70\mathrm{}$ keV was observed in the data taken at 75 keV, and its proton width was found to be $22\pm 3_{\mathrm{stat}}\pm 2_{\mathrm{target}}{}_{-1\mathrm{}\mathrm{beam}}^{+2\mathrm{}}$ neV.