Concept of a laser-plasma based electron source for sub-10 fs electron diffraction

TL;DR

This paper introduces a novel laser-plasma electron source capable of generating sub-10 femtosecond electron bunches at 5 MeV for ultrafast electron diffraction, demonstrating feasibility through simulations.

Contribution

It proposes and numerically validates a laser-plasma based electron source with ultrashort, high-coherence electron bunches suitable for diffraction applications, with a realistic beamline design.

Findings

Electron bunches of 5 fs duration and 1.5 fC charge are achievable.

Transverse coherence length exceeds 2 nm, suitable for diffraction.

The proposed system operates without temporal jitter in a realistic beamline.

Abstract

We propose a new concept of an electron source for ultrafast electron diffraction with sub-10~fs temporal resolution. Electrons are generated in a laser-plasma accelerator, able to deliver femtosecond electron bunches at 5 MeV energy with kHz repetition rate. The possibility of producing this electron source is demonstrated using Particle-In-Cell simulations. We then use particle tracking simulations to show that this electron beam can be transported and manipulated in a realistic beamline, in order to reach parameters suitable for electron diffraction. The beamline consists of realistic static magnetic optics and introduces no temporal jitter. We demonstrate numerically that electron bunches with 5~fs duration and containing 1.5~fC per bunch can be produced, with a transverse coherence length exceeding 2~nm, as required for electron diffraction.