New 19Ne level observed with a thick target 18F(p,p)18F measurement
Abstract
The rates of the 18F(p, α)15O and 18F(p, γ)19Ne reactions in astrophysical environments depend on the properties of 19Ne levels above the 18F + p threshold. There are at least 8 levels in the mirror nucleus 19F for which analogs have not been observed in 19Ne in the excitation energy range Ex = 6.4 - 7.6 MeV. These levels may significantly enhance the 18F + p reaction rates, and thus we have made a search for these levels by measuring the 1H(18F,p)18F excitation function over the energy range Ec.m. = 0.3 - 1.3 MeV. We have identified and measured the properties of a newly observed level at Ex = 7.420 ± 0.014 MeV, which is most likely the mirror to the Jπ = 7/2+19F level at 7.56 MeV. We have additionally found a significant discrepancy with a recent compilation for the properties of a 19Ne state at Ex = 7.5 MeV and set upper limits on the proton widths of missing levels. © 2005 Elsevier B.V. All rights reserved.