External electron injection, trapping, and emittance evolution in the blow-out regime

Abstract

In this work, we study electron side-injection and trapping in the blow-out regime in deep plasma channels. We analyze the maximum angle of injection, for which at least 90% of the injected electrons are trapped. We discuss the dependence of this angle on the electrons' initial energy and their injection positions. In the scope of a semi-analytical blow-out model, we show that the injection position is a less critical factor for trapping if electrons are injected into deep plasma channels. Photonic integrated circuit simulations and analytical approximations support our results from the semi-analytical model. Furthermore, a discussion of the temporal evolution of the normalized radial emittance during the trapping process and further acceleration is presented.