Collimated Hard X-Rays from Hybrid Laser and Plasma Wakefield Accelerators

TL;DR

This paper demonstrates a hybrid laser-plasma wakefield acceleration scheme that significantly enhances betatron radiation, producing highly collimated, high-flux hard X-rays with potential for compact source applications.

Contribution

It introduces a novel hybrid acceleration method combining laser and plasma wakefield techniques to produce brighter, more collimated hard X-ray sources than previous approaches.

Findings

Achieved a photon flux of over 10^14 photons per steradian above 5 keV.

Produced a critical photon energy of 71 keV with a divergence of approximately 6 mrad.

Demonstrated an order of magnitude increase in X-ray flux compared to prior reports.

Abstract

We report a synergistic enhancement of betatron radiation based on the hybrid laser and plasma wakefield acceleration scheme. Quasi-phase-stable acceleration in an up-ramp plasma density first generates GeV-energy electron beams that act as a drive beam for PWFA, which then further accelerates the witness beam to GeV energies, enhancing both photon energy and flux. A full width at half maximum divergence $(6.1 \pm 1.9)\times(5.8\pm 1.6) $ mrad$^2$ of betatron radiation, a critical energy of $71 \pm 8$ keV, and an average flux of more than $10^{14}$ photons per steradian above 5 keV were all experimentally obtained thanks to this scheme, which was an order of magnitude higher than the previous reports. Quasi-three-dimensional particle-in-cell simulations were used to model the acceleration and radiation of the electrons in our experimental conditions, establishing a new paradigm for compact collimated hard X-ray sources.