New 19Ne resonance observed using an exotic 18F beam

D. W. Bardayan, ORNL Physics Division
J. C. Blackmon, ORNL Physics Division
J. Gómez Del Campo, ORNL Physics Division
R. L. Kozub, Tennessee Technological University
J. F. Liang, ORNL Physics Division
Z. Ma, The University of Tennessee, Knoxville
D. Shapira, ORNL Physics Division
L. Sahin, The University of North Carolina at Chapel Hill
M. S. Smith, ORNL Physics Division


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 E x = 6.4-7.6MeV. We have made a search for these levels by measuring the 1H( 18F, p) 18F excitation function over the energy range E c.m. = 0.3-1.3MeV. We have identified and measured the properties of a newly observed level at E x = 7.420±0.014MeV, which is most likely the mirror to the J π = 7/2+19F level at 7.56MeV. This new level is found to increase the calculated 18F(p,α) 15O reaction rate by 16%, 63%, and 106% at T = 1, 2, and 3GK, respectively. © Società Italiana di Fisica / Springer-Verlag 2005.