HIGHER-ORDER EFFECTS IN ELECTROMAGNETIC DISSOCIATION OF FAST PARTICLES, A SOLUBLE MODEL AND APPLICATION TO LI-11

A general method for the calculation of second order effects in the Coulomb dissociation is presented in the small xi-limit avoiding the introduction of intermediate states. The amplitudes for a dipole excitation are analytically calculated in a simple model for the projectile with a zero-range force. The model is applied to the excitation of Li-11 at projectile energies of 28 and 800 MeV/nucleon. The angular and energy distribution of the fragments and post-acceleration effects are examined in first and second order perturbation theory as well as the sudden approximation.