Coulomb dissociation of ⁹Be: investigation of higher-order effects

We set up a simple model of the (⁸Be-n) final-state interaction at low relative energy. It reproduces the ( gamma ,n)-data in the relevant threshold region fairly well. The inverse low-energy neutron capture process (n, gamma ) is important for astrophysics, since it plays some role in stars, e.g. in nucleosynthesis. The aim of this model is to help us understand such capture processes from the Coulomb dissociation of light nuclei in collisions with heavy nuclei. If first-order electromagnetic interactions are responsible for the reaction, one can directly relate the cross section for dissociation to the corresponding photodisintegration process; therefore a study of higher-order effects may be helpful. We have studied them for the electromagnetic dissociation of ⁹Be in peripheral collisions with a ²⁰⁸Pb target. Using the saddle-point method we evaluate further the time dependence of the final-state wavefunction.