D(18F,pa)15N reaction applied to nova gamma-ray emission

Abstract

The 18F(p,alpha)15O reaction is recognized to be one of the most important reactions for nova gamma-ray astronomy as it governs the early E <= 511keV gamma emission. However in the nova temperature regime, its rate remains largely uncertain due to unknown low-energy resonance strengths. We report here the measurement of the D(18F,p)19F(alpha)15N one-nucleon transfer reaction, induced by a 14 MeV 18F radioactive beam impinging on a CD2 target; outgoing protons and 15N (or alpha-particles) were detected in coincidence in two silicon strip detectors. A DWBA analysis of the data resulted in new limits to the contribution of low-energy resonances to the rate of the 18F(p,alpha)15O reaction.Comment: Rapid Communication to appear in Phys. Rev. C., 4 pages and 4 figure