Tracking with wakefields in dielectric laser acceleration grating structures

TL;DR

This paper enhances a six-dimensional tracking scheme to analyze wakefield effects in dielectric laser acceleration structures, revealing limitations on electron bunch charge and potential stabilization methods through simulations and analytical comparisons.

Contribution

It introduces a wakefield upgrade to the DLAtrack6D tracking scheme, enabling detailed analysis of wakefield effects and stability in dielectric laser acceleration structures.

Findings

Wakefields limit relativistic electron bunch charge to a few femtocoulombs.

Scaling laws relate wakefield effects to geometrical parameters.

Identified instability mechanisms and potential stabilization strategies.

Abstract

Due to the tiny apertures of dielectric laser acceleration grating structures within the range of the optical wavelength, wakefields limit the bunch charge for relativistic electrons to a few femtocoulomb. In this paper, we present a wakefield upgrade of our six-dimensional tracking scheme DLAtrack6D in order to analyze these limitations. Simulations with CST Studio Suite provide the wake functions to calculate the kicks within each tracking step. Scaling laws and the dependency of the wake on geometrical changes are calculated. The tracking with wakefields is applied to beam and structure parameters following recently performed and planned experiments. We compare the results to analytical models and identify intensity limits due to the transverse beam breakup and strong head-tail instability. Furthermore, we reconstruct phase advance spectrograms and use them to analyze possible stabilization mechanisms.