An all-optical Compton source for single-exposure X-ray imaging

TL;DR

This paper demonstrates a compact all-optical Compton X-ray source using a plasma mirror and laser plasma accelerator, capable of single-shot radiography with high-energy femtosecond X-rays exceeding 100 keV.

Contribution

It introduces a novel single-pulse scheme employing a plasma mirror for efficient Compton scattering in laser plasma accelerators.

Findings

Produced quasi-monoenergetic electrons of ~150 MeV

Generated collimated X-ray beams with energies around 500 keV

Achieved single-shot radiography of centimeter-scale samples

Abstract

All-optical Compton sources are innovative, compact devices to produce high energy femtosecond X-rays. Here we present results on a single-pulse scheme that uses a plasma mirror to reflect the drive beam of a laser plasma accelerator and to make it collide with the highly-relativistic electrons in its wake. The accelerator is operated in the self-injection regime, producing quasi-monoenergetic electron beams of around 150 MeV peak energy. Scattering with the intense femtosecond laser pulse leads to the emission of a collimated high energy photon beam. Using continuum-attenuation filters we measure significant signal content beyond 100 keV and with simulations we estimate a peak photon energy of around 500 keV. The source divergence is about 13 mrad and the pointing stability is 7 mrad. We demonstrate that the photon yield from the source is sufficiently high to illuminate a centimeter-size sample placed 90 centimeters behind the source, thus obtaining radiographs in a single shot.