Growth rate calculation and one-dimensional simulation of an electromagnetically pumped FEL

Abstract

The dispersion relation of the scattered electromagnetic wave for an electromagnetically pumped free-electron laser is numerically solved. In addition, one-dimensional coupled Maxwell-lorentz equations are derived, and a particle simulation of the performance of the FEL amplifier in the long-pulse limit is performed for various pump conditions. The effect of the axial guide field, the beam energy and energy spread, and the pump strength on the system are investigated. Finally, the requirements on the electron beam quality and the parameter region of practical interest are discussed.