A compact tunable polarized X-ray source based on laser-plasma helical undulators

TL;DR

This paper introduces a compact, tunable polarized X-ray source using a laser-plasma helical undulator, capable of producing synchrotron-like radiation with adjustable intensity, spectra, and polarization, comparable to large synchrotron facilities.

Contribution

It proposes a novel plasma-based helical undulator design that enables tunable polarized X-ray radiation from laser wakefield accelerators.

Findings

Achieves millimeter-sized source with high peak brilliance.

Demonstrates flexible control over radiation polarization and spectra.

Brilliance comparable to third-generation synchrotrons.

Abstract

Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because their accelerating gradients are three orders of magnitude larger than traditional accelerators. However, X-ray radiation from such devices still lacks of tunability, especially the intensity and polarization distribution. Here we propose a tunable polarized radiation source from a helical plasma undulator based on plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of $2\times10^{19} photons/s/mm^{2}/mrad^{2}/0.1%$ bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with the third generation of synchrotron radiation facilities running at similar photon energies, suggesting that laser plasma based radiation sources are promising for advanced applications.