The cross sections of the 70Ge(p,gamma)71As and 76Ge(p,n)76As reactions have
been measured with the activation method in the Gamow window for the
astrophysical p process. The experiments were carried out at the Van de Graaff
and cyclotron accelerators of ATOMKI. The cross sections have been derived by
measuring the decay gamma-radiation of the reaction products. The results are
compared to the predictions of Hauser-Feshbach statistical model calculations
using the code NON-SMOKER. Good agreement between theoretical and experimental
S factors is found. Based on the new data, modifications of the optical
potential used for low-energy protons are discussed.Comment: Accepted for publication in Phys. Rev.