Experimental study of the astrophysically important Na 23 (α,p) Mg 26 and Na 23 (α,n) Al 26 reactions

The Na23(α,p)Mg26 and Na23(α,n)Al26 reactions are important for our understanding of the Al26 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 He4 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 Na23(α,p)Mg26 and the Na23(α,n)Al26 reactions are in good agreement with previous experiments and with statistical-model calculations. The astrophysical reaction rate of the Na23(α,n)Al26 reaction has been reevaluated and it was found to be larger than the recommended rate