Manifestations of the electron binding energies in the spectra of incoherently scattered gamma rays

In the spectra of $gamma$ rays with energies 412, 482, and 662 keV scattered by Pd, W, and Pb samples, steps were observed at energies lower than the initial values by amounts corresponding to the binding energy of the K electrons. This effect is ascribed to participation of the K shells in the incoherent scattering of the $gamma$ rays.