New limits for the 18F(p, α)15O rate in novae
The degree to which the (p, γ) and (p,α) reactions destroy 18F at temperatures ∼ 1- 4 times; 108 K is important for understanding the synthesis of nuclei in nova explosions and for using the long-lived radionuclide 18F, a target of gamma ray astronomy, as a diagnostic of nova mechanisms. The reactions are dominated by low-lying proton resonances near the 18F+p threshold (Ex = 6.411 MeV in 19Ne). To gain further information about these resonances, we have used the d(18F,p)19F neutron transfer reaction to selectively populate corresponding mirror states in 19F. The results would suggest 18F(p,γ)19Ne and 18F(p,α)15O reaction rates that are 2-3 times lower than reported previously. © 2005 Elsevier B.V. All rights reserved.