Electron Acceleration by a Relativistic Electron Plasma Wave in Inverse-Free-Electron Laser Mechanism

It has been revealed that a relativistic plasma wave, having an extremely large electric field, may be utilized for the acceleration of plasma particles. The large accelerating field gradient driven by a plasma wave is the basic motivation behind the acceleration mechanism. Such a plasma wave can be excited by a single laser in the form of wakefield in laser-plasma interactions. In this paper, we study the enhancement of electron acceleration by plasma wave in the presence of a wiggler magnetic field. Electrons trapped in the plasma wave are accelerated due to the additional resonance provided effectively by the wiggler field, which contributes in large energy gain of electrons during acceleration. The resonant enhancement of electron acceleration by the wiggler magnetic field has been validated by single particle simulations. The dependence of energy gain on plasma wave amplitude, initial electron energy, wiggler magnetic field strength has been investigated. Using the model, the involvement and importance of inverse free-electron laser mechanism in electron acceleration by the plasma wave was analyzed. A scaling law for electron energy optimization was proposed for future electron accelerator development.