Free-Electron Two-Quantum Stark Emission and Electric-Wiggler-Enhanced Three-Quantum Scattering in a Static Electric Wiggler Superposed on a Magnetic Wiggler

Abstract

We derive the cross section of scattering through three-quantum interaction of an electron with the incident laser field, the emitted photon, and a static axial electrostatic field superposed on a weak ( e B λ m /2π m c 2 ≪1) magnetic wiggler in which the magnetic wiggler acts as the sole zeroth-order perturbing classical field. In the derivation, we apply quantum-wiggler electrodynamics. Based on the result of the three-quantum scattering, it is found that an axial laser radiation cannot be self-launched in an electric wiggler alone or in the Smith–Purcell-type configuration. In a free-electron laser equivalent to the first free-electron laser except the magnetic wiggler being weak, we find that the laser radiation can be self-launched to the power level of 10 4 –10 5 times larger than the self-launched power of the latter.