Description
The generation and application of ultraintense laser-driven ultrashort electron pulses
Li-Xiang Hu1, Tong-Pu Yu1, Jianming Ouyang1, De-Bin Zou1, Zheng-Ming Sheng2
1Department of Physics, National University of Defense Technology, Changsha, China
2School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, China
The ultrashort energetic electron beam has significant potential for applications such as electron diffraction, four-dimensional electron imaging, electron injection into a free electron laser , and the production of ultrashort x-ray radiation sources with duration down to the attosecond level. In these fields, relativistic femtosecond or even attosecond electron bunches with a narrow energy spread, small divergence angle and large flux are of crucial importance. The ultrashort ultraintense laser pulse interaction with plasma has an inherent advantage in the generation of ultrashort electron pulses. However, due to the outward transverse ponderomotive force of the Gaussian laser pulse and Coulomb repulsion force, the produced electron beams disperse quickly along the transverse direction. The generated attosecond electron beams with a short duration (<50 fs), a large emission angle (> 20◦) and a low density (much less than the electron critical density), can’t be widely applied in various fields. Currently, it’s still a great challenge to generate high-quality attosecond electron pulses. In order to overcome these difficulties that have plagued people for many years, we propose a novel scheme to generate high-quality ultrashort electron pulses via the interaction of the Laguerre-Gaussian (LG) laser pulse and microstructure target through theoretical analysis and numerical simulation.
Firstly, we investigate the dynamics of ultraintense Laguerre-Gaussian laser pulses interacting with a microwire target and propose a novel physical scheme for the generation of high-quality attosecond electron bunch. When a relativistic LG-mode laser pulse sweeps a microwire target, annular electron bunches with attosecond duration are periodically dragged out of the left tip of the slice. Due to the radial laser electric field force exerted on the electrons, the annular bunches are tightly constrained near the target surface and steadily propagate along the microwire. Once leaving from the right tip of the target, the electron emission angle gradually decreases and each hollow electron bunch is converged into an electron disc. Under the action of the longitudinal electric field, electrons are continuously accelerated to 100s MeV. Secondly, we innovatively propose a scheme to generate such -rays via nonlinear Thomson scattering of a rotating relativistic electron sheet driven by a few-cycle twisted laser pulse interacting with a micro-droplet target. Three-dimensional numerical simulations demonstrate the -ray emission with 320 as duration and peak brilliance of 9.3×1024 photons/s/mrad2/mm2/0.1%BW at 4.3 MeV. These schemes may pave the way for the generation of high-quality attosecond electron bunches with low divergence and high beam charge, which may have wide-range applications in various domains.
[1] L. X. Hu et al., High Power Laser Sci. 12, e69 (2024).
[2] Y. Cao, L. X. Hu et al., New J. Phys. 25, 093045 (2023).
[3] Y. Cao, L. X. Hu et al., Opt. Express 29, 30223 (2021).
[4] L. X. Hu, et al., Plasma Phys. Control. Fusion 61, 025009 (2019).
