${}^{19}$Ne levels studied with the ${}^{18}$F($d,n$)${}^{19}$Ne${}^{*}$(${}^{18}$F+$p$) reaction

A good understanding of the level structure of ${}^{19}\mathrm{Ne}$ around the proton threshold is critical to estimating the destruction of long-lived ${}^{18}\mathrm{F}$ in novae. Here we report the properties of levels in ${}^{19}\mathrm{Ne}$ in the excitation energy range of 6.9 $⩽$ $E_x$ $⩽$ 8.4 MeV studied via the proton-transfer ${}^{18}\mathrm{F}(d,n){\mathrm{Ne}}^{*}$ reaction at the Holifield Radioactive Ion Beam Facility. The populated ${}^{19}\mathrm{Ne}$ levels decay by breakup into $p+{}^{18}\mathrm{F}$ and $\alpha +{}^{15}\mathrm{O}$ particles. The results presented in this manuscript are those of levels that are simultaneously observed from the breakup into both channels. An $s$-wave state is observed at 1468 keV above the proton threshold, which is a potential candidate for a predicted broad $J^{\pi }$ $=$ 1/2${}^{+}$ state. The proton and $\alpha$ partial widths are deduced to be ${\Gamma }_p$ $=$ 228 $\pm$ 50 keV and ${\Gamma }_{\alpha }$ $=$ 130 $\pm$ 30 keV for this state.

Figure 1

Partial spectrum from the breakup of ${}^{19}\mathrm{Ne}\to \alpha +{}^{15}\mathrm{O}$ above 3.3 MeV of $\alpha +{}^{15}\mathrm{O}$ relative energy. The fits are to the five resolved levels (I and III–VI). The red line is the sum of the individual peaks shown as black solid lines. State IV is the state of interest in the proton channel.

Figure 2

Spectrum from the breakup of ${}^{19}\mathrm{Ne}\to p+{}^{18}\mathrm{F}$ with fits to the five levels (I–V). The red line is the sum of the individual peaks shown as black solid lines. The excitation energies determined for ${}^{19}\mathrm{Ne}$ are listed in Table .

Figure 3

The Monte Carlo simulated (solid histogram) FWHM resolution for the reconstructed relative energy for $p+{}^{18}\mathrm{F}$. The observed experimental resolutions are indicated by solid circles. The square data point is the resolution that the peak at $E_{\mathrm{c}.\mathrm{m}.}$ $=$ 1.5 MeV would have when fitted with only one peak.

Figure 4

The calculated $p+{}^{18}\mathrm{F}$ coincidence efficiency for geometry used in this measurement.

Figure 5

The differential cross sections for $(d,n)$ transfer to the 7834-keV state in ${}^{19}\mathrm{Ne}$. These data are deduced from the $\alpha$-decay channel.