  We demonstrate that the transition photon radiation and pair creation can be
interpreted as a diffractive phenomenon in terms of the light-cone wave
functions in a way similar to the Good-Walker approach [6] to the diffraction
dissociation. Our formulas for spectra agree with those obtained by Baier and
Katkov [5] within the quasiclassical operator method. However, there is some
disagreement with earlier results by Garibyan [4].
