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arXiv · 2608.17555

Bright dual-pulse betatron X-ray generation from a laser wakefield accelerator

Bo Guo·Yang Wan·Shuang Liu·Xiaonan Ning·Jianfei Hua·Wei Lu
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Abstract

Pump-probe experiments using dual ultrashort X-ray pulses provide unique opportunities for resolving non-equilibrium dynamics initiated by intense X-ray excitation. Betatron radiation from laser wakefield accelerators offers femtosecond duration, micrometer-scale source size, and intrinsic synchronization with the driving laser, making it a promising candidate for compact ultrafast X-ray sources. Here, we experimentally demonstrate a high-flux, dual-pulse betatron X-ray source based on a density-tailored gas-mixture target. Two electron bunches are generated within a single plasma wakefield through ionization-induced and shock-front-triggered injection, subsequently producing twin X-ray pulses. The measured electron spectra and dual-component X-ray angular profiles, together with particle-in-cell simulations, identify the contributions of the two electron populations to the radiation. The total X-ray photon yield reaches the level of 10^{10} photons per shot with a 40-TW laser system. These results establish a compact, single-stage route toward high-flux dual-pulse betatron sources for laboratory-scale ultrafast X-ray spectroscopy.

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Bo Guo, Yang Wan, Shuang Liu, Xiaonan Ning, Jianfei Hua, Wei Lu. 2026-08-18. Bright dual-pulse betatron X-ray generation from a laser wakefield accelerator. https://arxiv.org/abs/2608.17555

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