Experimental Design and First Results from the Plasma-Driven Attosecond X-Ray Experiment at FACET-II

The ongoing Plasma-driven Attosecond X-ray source experiment (PAX) at FACET-II aims to produce coherent soft X-ray pulses of attosecond duration using a plasma wakefield accelerator [1]. These X-ray pulses can be used to study chemical processes where attosecond-scale electron motion is important. For this first stage of the experiment, PAX plans to demonstrate that <100 nm bunch length electron beams can be generated using the 10 GeV, 20 um duration beam accelerated in the FACET-II linac and using the plasma cell to give it a percent-per-micron chirp. The strongly chirped beam can then be compressed in a weak chicane to sub-100nm length, producing coherent synchrotron radiation in the final chicane magnet at wavelengths as low as 10s of nm. In this contribution we describe the results of recent experiments aiming to produce these ultra-compressed bunches and generate this single-cycle radiation, as well as the completion of the experimental setup of the PAX experiment.

[1] C. Emma, X.Xu et al APL Photonics 6, 076107 (2021)