Background: The nucleosynthesis of several proton-rich nuclei is determined
by radiative proton-capture reactions on unstable nuclei in nova explosions.
One such reaction is 23Mg(p,γ)24Al, which links the
NeNa and MgAl cycles in oxygen-neon (ONe) novae.
Purpose: To extract 23Mg(p,γ)24Al resonance
strengths from a study of proton-unbound states in 24Al, produced
via the 24Mg(3He,t) reaction.
Methods: A beam of 3He2+ ions at 50.7 MeV was used to produce
the states of interest in 24Al. Proton-triton angular correlations were
measured with a K=600 QDD magnetic spectrometer and a silicon detector array,
located at iThemba LABS, South Africa.
Results: We measured the excitation energies of the four lowest
proton-unbound states in 24Al and place lower-limits on Γp​/Γ
values for these four states. Together with USD-C shell-model calculations of
partial gamma widths, the experimental data are also used to determine
resonance strengths for the three lowest 23Mg(p,γ)24Al
resonances.
Conclusions: The energy of the dominant first 23Mg(p,γ)
resonance is determined to be Er​=481.4±1.1 keV, with a resonance
strength ωγ=18±6 meV