Compact Polarized X-Ray Source Based on All-Optical Inverse Compton Scattering

Abstract

Polarized x-ray source is a useful probe for many fields, such as fluorescence imaging, magnetic microscopy, and nuclear physics research. All-optical inverse Compton scattering source (AOCS) based on a laser wakefield accelerator (LWFA) has drawn great attention in recent years due to its compact scale and high performance, especially its potential to generate polarized x rays. Here, polarization-tunable AOCS x rays are generated by a plasma-mirror-based scheme. The linearly and circularly polarized AOCS x rays are measured to have the mean photon energy of $60(\ifmmode\pm\else\textpm\fi{}5)/64(\ifmmode\pm\else\textpm\fi{}3)$ keV and the single-shot photon yield of approximately $1.1/1.3\ifmmode\times\else\texttimes\fi{}{10}^{7}$. A Compton polarimeter is designed to diagnose the x-ray polarization states, demonstrating the polarization tunability of AOCS, and indicating that the average polarization degree of the linearly polarized AOCS is $75(\ifmmode\pm\else\textpm\fi{}3)\mathrm{%}$ within 18.2 mrad x-ray divergence.