SUBTHRESHOLD RESONANCE IN THE LI-6(D,ALPHA)HE-4 REACTION AND ITS ASTROPHYSICAL IMPLICATIONS

The total cross section of the Li-6(d,alpha)He-4 reaction has been mea sured for deuteron energies between 50 and 180 keV. From a detailed di storted-wave Born approximation analysis of the angular distributions and the excitation function up to 1 MeV it was possible to determine t he strength of a subthreshold resonance that dominates the cross secti on at sub-Coulomb energies and contributes significantly to the increa se of the astrophysical S factor at low energies. Consequently the ele ctron screening energy we have determined for the Li-6(d,alpha)He-4 re action is considerably smaller than the value given in previous works which overestimate the theoretical predictions. In addition the stella r reaction rate has been calculated up to a temperature of T-9=3.