Abstract:
13C(α,n)
16O is the main neutron source reaction of slow neutron capture (s) process in asymptotic giant branch (AGB) stars. The 6.356 MeV 1/2
+ subthreshold resonance in
17O plays an important role in the
13C(α,n)
16O reaction. The
13C(
11B,
7Li)
17O angular distributions were measured using HI-13 tandem accelerator and Q3D magnetic spectrograph, and then used to determine the α-width of the subthreshold resonant state which is currently the most uncertain parameter for determining the
13C(α,n)
16O reaction rate. By using the present α-width, the astrophysical
S-factor and the stellar rate of the
13C(α,n)
16O reaction were derived. This shed some light on the existing discrepancies up to a factor of 25 in
S-factors derived from different authors. The simulation of s-process in AGB stars shows that the new reaction rate produces 25% more Pb than the CF88 compilation.
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