Ultrafast Imaging of Laser Driven Shock Waves using Betatron X-rays from a Laser Wakefield Accelerator

TL;DR

This paper demonstrates the first use of betatron X-ray radiation from laser wakefield accelerators to ultrafastly image laser-driven shock waves in silicon, achieving high spatial and sub-100 fs temporal resolution, enabling new insights into rapid high-energy-density phenomena.

Contribution

It introduces the novel application of betatron radiation for ultrafast imaging of dynamic shock waves, bridging the gap between compact laser-based sources and high-resolution, high-speed diagnostics.

Findings

Successful radiography of laser-driven shock waves in silicon.

Spatial resolution comparable to synchrotron-based imaging.

Intrinsic temporal resolution below 100 femtoseconds.

Abstract

Betatron radiation from laser wakefield accelerators is an ultrashort pulsed source of hard, synchrotron-like x-ray radiation. It emanates from a centimetre scale plasma accelerator producing GeV level electron beams. In recent years betatron radiation has been developed as a unique source capable of producing high resolution x-ray images in compact geometries. However, until now, the short pulse nature of this radiation has not been exploited. This report details the first experiment to utilise betatron radiation to image a rapidly evolving phenomenon by using it to radiograph a laser driven shock wave in a silicon target. The spatial resolution of the image is comparable to what has been achieved in similar experiments at conventional synchrotron light sources. The intrinsic temporal resolution of betatron radiation is below 100 fs, indicating that significantly faster processes could be probed in future without compromising spatial resolution. Quantitative measurements of the shock velocity and material density were made from the radiographs recorded during shock compression and were consistent with the established shock response of silicon, as determined with traditional velocimetry approaches. This suggests that future compact betatron imaging beamlines could be useful in the imaging and diagnosis of high-energy-density physics experiments.