22Na(3He,d)23Mg reaction studies of states near the proton threshold and hydrogen burning of 22Na

Absolute determination of theNa22(p,γ)Sallaska1, Wrede2, Garcı́a3 et al. 2011Phys. Rev. C255340View full textAdd to dashboardCite

“…The strengths of the resonances at E p = 45 and 70 keV are too low to be measured directly due to the Coulomb barrier but have been included in the calculation of the reaction rate derived from Ref. [28], based on the ( 3 He,d) spectroscopic factors of Ref [19].…”

“…k The value from Ref. [25] is used, as this gamma ray was obscured by 19 F background in our measurements.…”

“…Consequently, the rate is dependent on the energies and strengths of these resonances, which have been investigated both indirectly and directly in the past. Indirect information on potential 22 Na(p, γ) resonances has been derived from measurements of the 24 Mg(p, d) [17], 25 Mg(p, t) [18], and 22 Na( 3 He,d) [19] reactions, and from the beta-delayed proton-and gammadecays of 23 Al [20][21][22]. The first published attempt to measure the 22 Na(p, γ) reaction directly employed a chemically prepared, radioactive 22 Na target and produced only upper limits on the resonance strengths [23].…”

Synthesis of the elements in stars: forty years of progress

“…Schmidt et al (1995) have used the 22 Na( 3 He,d) reaction to determine the strengths of low-energy resonances and direct (p,␥) measurements have also been performed by Seuthe et al (1990) and by Stegmü ller et al (1996). For pure hydrogen at a density of 10 3 g/cm 3 , the ␤ ϩ decay and (p,␥) lifetimes are equal for temperatures T 9 =0.039-0.068, where the range in temperature reflects the uncertainty in the reaction rate.…”

β decay of proton-rich nucleusAl23and astrophysical consequences

“…The corresponding resonances are excited states in 23 Mg, some of them populated in the β decay of 23 Al, including the isobaric analog state of its ground state, which can be identified by its preferential population. However, the reaction rate in stellar environments is still uncertain even after a few direct measurements [13,14] and many spectroscopic studies [11,12,[15][16][17]. The major problem is that at this excitation energy, there is a large density of states that cannot easily be separated and identified.…”