Cross section and astrophysical S-factor measurements of radiative proton capture on lead-102, tin-116, and alpha capture on tin-112 at low energies

The cross section and astrophysical S-factor measurements for 102Pd(p,gamma)103Ag and 116Sn(p,gamma) 117Sb reactions have been performed in the proton energy range 2.6 to 4.25 MeV using the 11MV FN Tandem Van de Graaff accelerator at the University of Notre Dame. In addition, the 112Sn(alpha,gamma) 116Te reaction has been measured over the alpha beam energy range 7.0 to 10.5 MeV. The results have been compared to those of statistical model calculations generated by the NON-SMOKER code. Since low cross sections are involved, an activation technique has been used, whereby gamma rays have been detected off-line by two HPGe detectors in a low background environment. These measurements will be used to judge the applicability of the NON-SMOKER code to calculations of nucleosynthesis in the gamma- and rp-processes in explosive astrophysical environments, where currently almost no experimental data exist in the mass region beyond A = 100.