Search for astrophysically important ¹⁹Ne levels with a thick-target ¹⁸F(p,p)¹⁸F measurement

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 eight levels in the mirror nucleus ¹⁹F for which analogs have not been observed in ¹⁹Ne in the excitation energy range E_x=6.4–7.6 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 E_c.m.=0.3–1.3 MeV. We have identified and measured the properties of a newly observed level at E_x=7.420±0.014 MeV, which is most likely the mirror to the J^π=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 E_x=7.5 MeV and set upper limits on the proton widths of missing levels.