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arXiv · 2408.04892

Laser-triggered THz emission from near critical density targets

V. Yu. Bychenkov·A. V. Brantov·M. G. Lobok·A. S. Kuratov
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Abstract

Femtosecond laser pulse propagation in a relativistic self-trapping regime (RST) in a near-critical density plasma makes it possible to maximize the total charge of the accelerating electrons and laser-to-electrons conversion rate, that can be used to provide a large amount of the THz range coherent transition radiation. The three-dimensional particle-in-cell simulations demonstrate how such transition radiation generates when electrons escape into vacuum either from the low-density target itself, or after passing through a thin foil located at the target end. Advantage of the RST regime for generation of THz pulses is clearly demonstrated as compared to laser irradiation of such a standard target as a foil with preplasma on its front side. Simulation performed has shown that for the optimized laser-target matching a 2-J femtosecond laser pulse is able to produce quasi-unipolar Thz pulses with energy exceeding 100 mJ.

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V. Yu. Bychenkov, A. V. Brantov, M. G. Lobok, A. S. Kuratov. 2024-08-09. Laser-triggered THz emission from near critical density targets. https://doi.org/10.1103/physreve.110.065203

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