Unified analysis for calculating the amplification gain of Cerenkov laser in the single-particle and collective regimes

Abstract

In this paper, we introduce a unified analytical model to describe both the single-electron and the collective modes of interaction in the Cerenkov laser. Although the basic formulations of the model are based on the single-electron interaction with the electromagnetic wave, the characteristics of the wave-wave interaction associated with the collective model are also determined. The transition regime between the single-electron and the collective models is explored. The electron relaxation effect caused by the asymmetric Coulomb forces among the electrons is taken into account. The essential results of this paper agree with those predicted by previous theories at the limits of the single-electron and collective.

Space-charge effects and gain in Cherenkov free-electron lasers

“…The presence of the positive ions in (or around) the electron beam greatly influences the electron relaxation. In the current quantum mechanical analysis, the electron relaxation process is viewed as a phase distortion in the electron wave and represents the Coulomb repulsion forces between electrons [29][30][31].…”