2023/11/25 by Chen Yao, Yao, C., Junjie Li +12 · 1 citation
Chemistry · Engineering · Physics and Astronomy · #FOS: Physical sciences #Laser-Matter Interactions and Applications #Laser-induced spectroscopy and plasma #Mass Spectrometry Techniques and Applications #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.2311.14956
openalex publication_date 2023/11/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the hot electrons generated from two-plasmon decay (TPD) instability driven by laser pulses with intensity modulated by a frequency Δωm. Our primary focus lies on scenarios where Δωm is on the same order of the TPD growth rate γ0 ( Δωm ∼ γ0), corresponding to moderate laser frequency bandwidths for TPD mitigation. With Δωm conveniently modeled by a basic two-color scheme of the laser wave fields in fully-kinetic particle-in-cell simulations, we demonstrate that the energies of TPD modes and hot electrons exhibit intermittent evolution at the frequency Δωm, particularly when Δωm ∼ γ0. With the dynamic TPD behavior, the overall ratio of hot electron energy to the incident laser energy, fhot, changes significantly with Δωm. While fhot drops notably with increasing Δωm at large Δωm limit as expected, it goes anomalously beyond the hot electron energy ratio for a single-frequency incident laser pulse with the same average intensity when Δωm falls below a specific threshold frequency Δωc. We find this threshold frequency primarily depends on γ0 and the collisional damping rate of plasma waves, with relatively lower sensitivity to the density scale length. We develop a scaling model characterizing the relation of Δωc and laser plasma conditions, enabling the potential extention of our findings to more complex and realistic scenarios.