Destruction of 18F via 18F(p,a)15O Burning Through the Ec.m. = 665 keV Resonance
Knowledge of the astrophysical rate of the {sup 18}F(p,a){sup 15}O reaction is important for understanding the {gamma}-ray emission expected from novae and heavy-element production in x-ray bursts. The rate of this reaction is dominated at temperatures above {approx}0.4 GK by a resonance near 7.08 MeV excitation energy in {sup 19}Ne. The {sup 18}F(p,a){sup 15}O rate has been uncertain in part because of disagreements among previous measurements concerning the resonance strength and excitation energy of this state. To resolve these uncertainties, we have made simultaneous measurements of the {sup 1}H({sup 18}F,p){sup 18}F and {sup 1}H({sup 18}F,a){sup 15}O excitation functions using a radioactive {sup 18}F beam at the ORNL Holifield Radioactive Ion Beam Facility. A simultaneous fit of the data sets has been performed, and the best fit was obtained with a center-of-mass resonance energy of 664.7 {+-} 1.6 keV (E{sub x} = 7076 {+-} 2 keV), a total width of 39.0 {+-} 1.6 keV, a proton branching ratio of {Lambda}{sub p}/{Lambda} = 0.39 {+-} 0.02, and a resonance strength of {omega}{gamma} = 6.2 {+-} 0.3 keV.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 829243
- Report Number(s):
- P00-109251; PRVCAN; TRN: US0602174
- Journal Information:
- Physical Review, C (Nuclear Physics), Vol. 63, Issue 6; ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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