  The optical potential of halo and weakly bound nuclei has a long range part
due to the coupling to breakup that damps the elastic scattering angular
distributions. In order to describe correctly the breakup channel in the case
of scattering on a heavy target, core recoil effects have to be taken into
account. We show here that core recoil and nuclear breakup of the valence
nucleon can be consistently taken into account. A microscopic absorptive
potential is obtained within a semiclassical approach and its characteristics
can be understood in terms of the properties of the halo wave function and of
the reaction mechanism. Results for the case of medium to high energy reactions
are presented.
