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arXiv · 2304.02876

Anisotropic field ionization in nano-clusters mediated by Brunel-electron driven plasma waves

Xiaohui Gao
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Abstract

Ionization is one of the most fundamental processes in intense laser-matter interaction. It is extremely efficient for clusters in laser fields and often leads to surprisingly high charge states at moderate laser intensities. Here we reveal a novel ionization mechanism in laser-cluster interaction through particle-in-cell simulations. As the laser field ionizes a cluster, Brunel electrons pushed back into the clustered plasma form an attosecond bunches, impulsively exciting plasma oscillation. The resulting localized wake field further ionizes the cluster, causing a highly ionized rod-like core along the polarization axis. This anisotropic ionization is prominent using few-cycle pulses and may be washed out using longer pulses due to collisional ionization. This newly identified ionization channel can potentially provide complicated site-specific control of ionization in nanometer-scale targets.

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Xiaohui Gao. 2023-04-06. Anisotropic field ionization in nano-clusters mediated by Brunel-electron driven plasma waves. https://doi.org/10.1103/physreva.108.033109

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