Time-dependent analysis of the Coulomb breakup method for determining the astrophysical S factor - art. no. 054612

The time-dependent mesh method is applied to the calculation of the Coulomb breakup of a projectile into two charged fragments. The projectile is desc ribed in the potential model and its center of mass is assumed to follow a classical trajectory. The approach is compared with the first-order time-de pendent perturbation approximation based on an electric dipole interaction under the same model assumptions. The numerical technique is applied to the F-17+ Pb-208 --> O-16+p+ Pb-208 breakup in order to test the validity of t he extraction of the E1 astrophysical S factor for the O-16(p,gamma) F-17 r adiative capture reaction to the F-17 ground state. After carefully testing the validity of the numerical technique, we show that the accuracy of the astrophysical S factor extracted in such a way is better than 5% for projec tile velocities above about 0.25c in large domains of impact parameters and relative energies between the fragments. Breakup cross sections are also c alculated as a function of the relative energy between the fragments at dif ferent projectile velocities. A test calculation is performed for the break up of the weakly bound 1/2(+) excited state of F-17. A comparison is presen ted and discussed with the only existing experimental differential cross se ction at the projectile energy of 10 MeV/nucleon.