Generation and acceleration of high brightness electrons beams bunched at X-ray wavelengths using plasma-based acceleration

TL;DR

This paper demonstrates a method to generate high-brightness, density-modulated electron beams at angstrom-scale wavelengths using plasma wakefields and laser-induced density modulation, enabling coherent X-ray production.

Contribution

The authors introduce a novel plasma-based scheme combining density downramp injection and laser-induced density modulation to produce electron beams with sub-nanometer wavelength density structures.

Findings

Simulations show generation of electron beams modulated at 10-100 angstroms.

The scheme produces high-quality, stable electron beams suitable for X-ray generation.

Potential to generate hundreds of GW coherent X-ray radiation.

Abstract

We show using particle-in-cell (PIC) simulations and theoretical analysis that a high-quality electron beam whose density is modulated at angstrom scales can be generated directly using density downramp injection in a periodically modulated density in nonlinear plasma wave wakefields. The density modulation turns on and off the injection of electrons at the period of the modulation. Due to the unique longitudinal mapping between the electrons' initial positions and their final trapped positions inside the wake, this results in an electron beam with density modulation at a wavelength orders of magnitude shorter than the plasma density modulation. The ponderomotive force of two counter propagating lasers of the same frequency can generate a density modulation at half the laser wavelength. Assuming a laser wavelength of $0.8\micro\meter$, fully self-consistent OSIRIS PIC simulations show that this scheme can generate high quality beams modulated at wavelengths between 10s and 100 angstroms. Such beams could produce fully coherent, stable, hundreds of GW X-rays by going through a resonant undulator.