The unbound nucleus $^{ 18}$Na, the intermediate nucleus in the two-proton radioactivity of $^{ 19}$Mg, was studied by the measurement of the resonant elastic scattering reaction $^{ 17}$Ne(p,$^{ 17}$Ne)p performed at 4 A.MeV. Spectroscopic properties of the low-lying states were obtained in a R-matrix analysis of the excitation function. Using these new results, we show that the lifetime of the $^{ 19}$Mg radioactivity can be understood assuming a sequential emission of two protons via low energy tails of $^{ 18}$Na resonances.
Categories: nucl-ex