Modulation of an electron beam by stimulated bremsstrahlung scattering

Electron beam modulation by stimulated bremsstrahlung scattering (SBS) is investigated by regarding each atom as a dynamical system. Since SBS is important at nonrelativistic energies, the wave function of the atom/scattered-electron system is found using the Schroedinger equation. It is shown that the current density of the scattered electrons is modulated, and in contrast to the case of SBS by an external potential, both the fundamental and harmonic wave frequencies and their combination frequencies with atomic transitions are modulated. The example of SBS for a hydrogen atom is considered and it is shown that if the atoms are initially unexcited, only the elastic electron-atom collisions will produce modulation during SBS. An analysis of how the modulation changes when many atoms are involved in the scattering is also considered.