  We study the corrections of first order electromagnetic excitation due to
higher order electromagnetic interactions. An effective operator is introduced
which takes these effects into account in the sudden approximation. Evaluating
the matrix-elements of this operator between the relevant states corrections to
the first order result are obtained in a simple way. As an example we discuss
the excitation of the first excited state in 11Be. It tends to improve the
agreement between experiment and theory.

Nuclear Theory