A tip-based source of femtosecond electron pulses at 30keV

TL;DR

This paper introduces a nano-scale, tip-based photoelectron source capable of generating 30 keV femtosecond electron pulses suitable for time-resolved diffraction, combining experimental validation with simulations.

Contribution

It presents a novel tip-based electron source optimized for ultrashort pulses, achieving 37 fs duration at 30 keV, with demonstrated femtosecond laser-triggered operation.

Findings

Electron pulses of 37 fs duration at 30 keV achieved.

Excellent agreement between simulations and experimental measurements.

Source exhibits femtosecond laser-triggered operation.

Abstract

We present a nano-scale photoelectron source, optimized towards ultrashort pulse durations and well-suited for time-resolved diffraction experiments. A tungsten tip, mounted in a suppressor-extractor electrode configuration, allows the generation of 30 keV electron pulses with an estimated pulse duration of 37 fs at the gun exit. We infer the pulse duration from particle tracking simulations, which are in excellent agreement with experimental measurements of the electron-optical properties of the source. We furthermore demonstrate femtosecond laser-triggered operation. Besides the short electron pulse duration, a tip-based source is expected to feature a large transverse coherence as well as a nanometric emittance.