High-brightness betatron X-ray source driven by SULF-1 PW laser

The betatron radiation source, emitted as the electrons are transversally wiggled during acceleration within the wakefield, features a micrometer-scale source size, femtosecond-scale pulse duration, milliradian-level divergence angles, and a broad spectrum exceeding beyond tens of keV. It is suitable for high-contrast imaging of minute structures and for the investigation of interdisciplinary ultrafast processes. Here we present a betatron X-ray source by producing a high-charge, high-energy electron beam through a laser wakefield accelerator driven by the 1 PW/0.1 Hz laser system in Shanghai Superintense Ultrafast Laser Facility (SULF). The maximum X-ray flux reaches up to 4×109 photons per shot above 5 keV, with a critical energy of 22±5 keV. Correspondingly, a peak brightness of 1.0×1023 photons·s-1·mm-2·mrad-2·0.1%BW-1 can be surmised in the experiment, comparable to that of the 3rd generation synchrotron light sources. Additionally, the imaging capability of betatron X-ray source has been validated, laying the foundation for future imaging applications.