Sources of ultrafast broadband X-ray driven by high-power lasers at ELI Beamlines facility*

The realization of compact broadband X-ray sources is one of the most intriguing applications of laser-plasma accelerator (LPA). The state-of-the-art laser plasma X-ray sources can provide a photon flux of over 10¹¹ photons/shot [1] and the flux can be further enhanced using novel techniques [2,3]. In this contribution, we will summarize the recently commissioned compact X-ray sources at ELI beamlines. The Gammatron beamline [4] provides a collimated, bright, and partially coherent beam of X-ray photons for multidisciplinary applications. The beamline is equipped with all necessary hardware, including in-house designed broadband X-ray mirrors [5], facilitating pump-probe experiments. Additionally, we have developed a novel optical probing technique employing multiple passes of the probe through the object to increase phase sensitivity and provide high sensitivity for the characterization of a low-density gas target an LPA [6-8].

The second LPA-based Betatron source is being developed at the ELI plasma physics platform (P3)[9-10]. This X-ray source is aimed to serve as a backlighter for laser-matter interaction experiments, such as HEDP [11] and advanced plasma physics experiments.

Besides, we will report a new mechanism of relativistic emission of radiation from plasma mirrors (RIME) that is identified with an extraordinary property that instead of following specular reflection, the radiation is emitted in the direction along the plasma mirror surface [12].