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Using a 33 MeV proton beam with our Enge split-pole spectrograph, we measured the ${Q}_{0}$ values of the $^{24}\mathrm{Mg}(p,t)^{22}\mathrm{Mg}$ and $^{28}\mathrm{Si}(p,t)^{26}\mathrm{Si}$ reactions relative to that of the $^{16}\mathrm{O}(p,t)^{14}\mathrm{O}$ reaction. Data were obtained at scattering angles of ${15}^{\ifmmode^\circ\else\textdegree\fi{}}$ and ${25}^{\ifmmode^\circ\else\textdegree\fi{}}$. Based on the masses of $^{24}\mathrm{Mg}$, $^{28}\mathrm{Si}$, $^{16}\mathrm{O}$, ${}^{14}O,p$, and t, we determined the mass excesses of $^{22}\mathrm{Mg}$ and $^{26}\mathrm{Si}$ to be \ensuremath{-}400.5(1.0) and \ensuremath{-}7139.5(1.0) keV, respectively. Our result for the mass of $^{22}\mathrm{Mg}$ is in excellent agreement with recent high-precision measurements.

The long-lived radioactive nuclide $^{22}\mathrm{Na}$ $({t}_{1∕2}=2.6\phantom{\rule{0.3em}{0ex}}\mathrm{yr})$ is an astronomical observable for understanding the physical processes of oxygen-neon novae. Yields of $^{22}\mathrm{Na}$ in these events are sensitive to the unknown total rate of the $^{21}\mathrm{Na}(p,\ensuremath{\gamma})^{22}\mathrm{Mg}$ reaction. Using a high intensity $^{21}\mathrm{Na}$ beam at the $\mathrm{TRIUMF}\text{\ensuremath{-}}\mathrm{ISAC}$ facility, the strengths of seven resonances in $^{22}\mathrm{Mg}$, of potential astrophysical importance, have been directly measured at center of mass energies from ${E}_{\mathrm{c.m.}}=200$ to $1103\phantom{\rule{0.3em}{0ex}}\mathrm{keV}$. We report the results obtained for these resonances and their respective contributions to the $^{21}\mathrm{Na}(p,\ensuremath{\gamma})^{22}\mathrm{Mg}$ rate in novae and x-ray bursts, and their impact on $^{22}\mathrm{Na}$ production in novae.

The 21Na(p,gamma)22Mg reaction is expected to play an important role in the nucleosynthesis of 22Na in oxygen-neon novae. The decay of 22Na leads to the emission of a characteristic 1.275 MeV gamma-ray line. This report provides the first direct measurement of the rate of this reaction using a radioactive 21Na beam, and discusses its astrophysical implications. The energy of the important state was measured to be E(c.m.)=205.7+/-0.5 keV with a resonance strength omegagamma=1.03+/-0.16(stat)+/-0.14(sys) meV.

The DRAGON recoil separator facility, designed to measure the rates of radiative proton and alpha capture reactions important for nuclear astrophysics, is now operational at the TRIUMF‐ISAC radioactive beam facility in Vancouver, Canada. We report on first measurements of the 21Na(p,γ)22Mg reaction rate with radioactive beams of 21Na.

The Facility for Rare Isotope Beams (FRIB) is a United States Department of Energy user facility currently under construction on the campus of Michigan State University. Based on a 400 kW, 200 MeV/u heavy-ion driver linac, FRIB will deliver high-quality fast, thermalized, and re-accelerated beams of rare isotopes with unprecedented intensities to a variety of experimental areas and equipment. New science opportunities at the frontiers of nuclear structure, nuclear astrophysics, fundamental symmetries, and societal applications will be enabled by this future world-leading rare-isotope beam facility.

The new DRAGON recoil separator facility, designed and built to measure directly the rates of radiative proton and alpha capture reactions important for nuclear astrophysics, is now in operation at the TRIUMF‐ISAC radioactive beams facility in Vancouver, Canada. Experiments have been conducted for the first time on the 21Na(p,γ)22Mg reaction. The evolution of nova explosions, and particularly their 22Na abundance, depends sensitively on this reaction rate. The radioactive 21Na beam with an intensity of up to 5 × 108 /s was directed onto a windowless hydrogen gas target (3.8 × 1018 H atoms/cm2). Prompt reaction gamma rays were detected using a BGO array and separated reaction products detected using a silicon strip detector at the end of the 20.8 m recoil mass separator. Yield measurements recording simultaneously singles and coincident signals were performed by scanning in energy over the known resonance reported previously in 22Mg at Ecm = 212 keV, and in addition, over a strong resonance observed at Ecm...

A small fraction (< 1%) of presolar SiC grains is suggested to have been formed in the ejecta of classical novae. The 29P(p,γ)30S reaction plays an important role in understanding the Si isotopic abundances in such grains, which in turn provide us with information on the nature of the probable white dwarf progenitor’s core, as well as the peak temperatures achieved during nova outbursts, and thus the nova nucleosynthetic path. The 29P(p,γ)30S reaction rate at nova temperatures is determined by two low-lying 3+ and 2+ resonances above the proton threshold at 4399 keV in 30S. Despite several experimental studies in the past, however, only one of these two states has only been observed very recently. We have studied the 30S nuclear structure via the 32S(p,t) 30S reaction at 5 laboratory angles between 9° to 62°. We have observed 14 states, eleven of which are above the proton threshold, including two levels at 4692.7 ± 4.5 keV and 4813.8 ± 3.4 keV that are candidates for the 3+ and the previously “issing” 2+ state, respectively.

A small fraction (< 1%) of presolar SiC grains is suggested to have been formed in the ejecta of classical novae. The 29P(p,γ)30S reaction plays an important role in understanding the Si isotopic abundances in such grains, which in turn provide us with information on the nature of the probable white dwarf progenitor's core, as well as the peak temperatures achieved during nova outbursts, and thus the nova nucleosynthetic path. This rate at nova temperatures is determined by two low-lying 3+ and 2+ resonances above the proton threshold at 4399 keV in 30S. Despite several experimental studies in the past, however, these two states have only been observed very recently. We have studied the 30S nuclear structure via the 32S(p,t)30S reaction at 5 laboratory angles between 9° to 62°. We have observed 14 states, eleven of which are above the proton threshold, including two levels at 4692.7 ± 4.5 keV and 4813.8 ± 3.4 keV that are candidates for the 3+ and the previously "missing" 2+ state, respectively.