Measurement of the F 19 ( p , γ ) Ne 20 reaction and interference terms from E c . m . = 200 − 760 keV

The 19 F(p, γ) 20 Ne reaction represents the only breakout path for the carbon-nitrogen-oxygen cycle operating at temperatures below T = 0.1 GK, an energy regime important for main-sequence hydrogen burning as well as hydrogen burning in asymptotic giant branch stars. Large experimental uncertainties exist due to unknown low energy direct and resonant reaction contributions that have been difficult to study because of the high γ-ray background from the 19 F(p, α 2 γ) reaction. A new detection technique has been developed at the University of Notre Dame to measure the 19 F(p, y) and 19 F(p, α i γ) reactions over an energy range of E c.m, = 200-760 keV. The analysis was carried out in a Breit-Wigner framework. This allowed a new determination of the resonance parameters as well as a first measurement of the signs of the interference terms. Partial widths and resonance strengths are reported for the resonances in this region.