Laser-driven high-flux and high efficiency betatron radiation in parabolic plasma channel

Laser wakefield acceleration (LWFA) has emerged as a promising approach for generating compact, high-energy electron beams and high flux X-ray radiation sources. In this work, we investigate the effects of different plasma density profiles—uniform plasma and a parabolic plasma channel—on electron acceleration and betatron radiation using three-dimensional particle-in-cell simulations. The results indicate that the parabolic channel can efficiently guide multi-hundred-terawatt laser pulses, enabling long-distance propagation and stable wakefield formation. Consequently, high-charge electron beams with total charge reaching tens of nC are generated. Compared with the uniform plasma case, the betatron radiation produced in the parabolic channel shows significantly improved properties, including higher critical photon energy, larger photon yield, and 3–4 times higher laser-to-photon energy conversion efficiency. These enhancements are attributed to stronger laser guiding and sustained accelerating fields within the parabolic channel.