Experimental study of the astrophysically important Na23(α,p)Mg26 and

Abstract

The 23 Na(α, p) 26 Mg and 23 Na(α, n) 26 Al reactions are important for our understanding of the 26 Al abundance in massive stars. The aim of this work is to report on a direct and simultaneous measurement of these astrophysically important reactions using an active target system. The reactions were investigated in inverse kinematics using 4 He as the active target gas in the detector.We measured the excitation functions in the energy range of about 2 to 6 MeV in the center of mass. We have found that the cross sections of the 23 Na(α, p) 26 Mg and the 23 Na(α, n) 26 Al reactions are in good agreement with previous experiments, and with statistical-model calculations. The astrophysical reaction rate of the 23 Na(α, n) 26 Al reaction has been re-evaluated and it was found to be larger than the recommended rate. * mavila@anl.gov

Experimental study of Ar38+α reaction cross sections relevant to the Ca41 abundance in the solar system

“…MUSIC is an active-target detector consisting of a cathode, a Frisch grid and an anode. It has close to 100% detection efficiency and has previously been used in studying (α, p) and (α, n) reactions of astrophysical interest [25].…”

Study of (α,p) and (α,n)Avila1, Rehm2, Almaraz-Calderon3 et al. 2017Nuclear Instruments and Methods in Physics Research Section A: Self Cite240161View full textAdd to dashboardCite

“…In this plot (also shown in Ref. [18] in the centerof-mass frame. The normalization of the cross section is performed by using the number of beam particles which are simultaneously measured in the detector.…”

“…8 (from Ref. [18]), where the (α p , ) data are shown by red circles for the lower beam energy and by red triangles for the higher beam energy. Similarly the (α n , ) cross sections are shown by blue diamonds for the lower energy and blue squares for the higher beam energy, respectively.…”

Uncertainty of the astrophysical O17,18(α,n)Ne20,21Mohr1 2017Phys. Rev. C9070View full textAdd to dashboardCite

“…Such a branching ratio is expected from the negative Q-value of the (p,α) reaction and the resulting strong Coulomb suppression of the higher-lying final states in 17 20 Ne data [24] because of the small Q-value of the (α,n) reaction.…”

“…Further total (α,n) data are measured by detection of the 20 Ne recoil nucleus in inverse kinematics [24]. The (α,n0) and (α,n1) data are scaled by factors of 10 −2 and 10 −4 for better visibility.…”