Efficient generation of divergent and collimated hot electrons via a novel multi-beam two-plasmon decay and stimulated Raman scattering mechanism

Meng K. Y.; Cai Z. H.; Li J.; Yao C.; Hao L.; Zhou F. X.; Yan R.; Zheng J.

doi:10.1063/5.0305281

Volume 11 Issue 3

May 2026

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Meng K. Y., Cai Z. H., Li J., Yao C., Hao L., Zhou F. X., Yan R., Zheng J.. Efficient generation of divergent and collimated hot electrons via a novel multi-beam two-plasmon decay and stimulated Raman scattering mechanism[J]. Matter and Radiation at Extremes, 2026, 11(3): 037402. doi: 10.1063/5.0305281

Citation:

Meng K. Y., Cai Z. H., Li J., Yao C., Hao L., Zhou F. X., Yan R., Zheng J.. Efficient generation of divergent and collimated hot electrons via a novel multi-beam two-plasmon decay and stimulated Raman scattering mechanism[J]. Matter and Radiation at Extremes, 2026, 11(3): 037402. doi: 10.1063/5.0305281

Citation:

Meng K. Y., Cai Z. H., Li J., Yao C., Hao L., Zhou F. X., Yan R., Zheng J.. Efficient generation of divergent and collimated hot electrons via a novel multi-beam two-plasmon decay and stimulated Raman scattering mechanism[J]. Matter and Radiation at Extremes, 2026, 11(3): 037402. doi: 10.1063/5.0305281

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Efficient generation of divergent and collimated hot electrons via a novel multi-beam two-plasmon decay and stimulated Raman scattering mechanism

doi: 10.1063/5.0305281

Meng K. Y.^1
,,
Cai Z. H.^1
,,
Li J.^{1, 2
,
,
,},
Yao C.^{1, 3
,},
Hao L.^3
,,
Zhou F. X.^4
,,
Yan R.^{2, 4
,
,
,},
Zheng J.^{1, 2
,}

1.
Department of Plasma Physics and Fusion Engineering and CAS Key Laboratory of Frontier Physics in Controlled Nuclear Fusion, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China
2.
Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, People’s Republic of China
3.
Institute of Applied Physics and Computational Mathematics, Beijing 100088, People’s Republic of China
4.
Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China

More Information

Corresponding author: a)Authors to whom correspondence should be addressed: junlisu@ustc.edu.cn and ruiyan@ustc.edu.cn
Received Date: 2025-10-05
Accepted Date: 2026-01-28

Available Online: 2026-05-01

Publish Date: 2026-05-28

Abstract

Abstract

In inertial confinement fusion (ICF) implosions, the preheating risks associated with hot electrons generated by laser–plasma instabilities are contingent upon the angular characteristics of these hot electrons for a given total energy. Using particle-in-cell simulations, we reveal a novel multi-beam collaborative mechanism of two-plasmon decay (TPD) and stimulated Raman scattering (SRS), and investigate the angular variations of hot electrons generated from this shared TPD–SRS (STS) instability driven collectively by dual laser beams with varying incident angles θ_in (from 24° to 55° at the incident plane) for typical ICF conditions. In the simulations with θ_in ≳ 44°, STS emerges as the dominant mechanism responsible for hot-electron generation, leading to a wide angular distribution of hot electrons that exhibit both pronounced divergent and collimated components. The common Langmuir wave associated with STS plays a crucial role in accelerating both components. By appropriate modeling of the STS common wave gains, we establish scaling relations between these gains and the energies of collimated and divergent hot electrons. These relations reveal that the divergent hot electrons are more sensitive to variations in gain compared with the collimated electrons. Additionally, the calculated gains qualitatively predict the asymmetry in hot-electron angular distributions when the density gradients deviate from the bisector of the laser beams. Our findings offer insights for hot-electron generation with multiple beams, potentially complementing previous experiments that underscore the critical role of overlapped intensity from symmetric beams within the same cone and the dominance of dual-beam coupling.

The authors have no conflicts to disclose.
Conflict of Interest
K. Y. Meng: Conceptualization (equal); Data curation (lead); Formal analysis (lead); Investigation (lead); Methodology (equal); Software (equal); Validation (lead); Visualization (equal); Writing – original draft (lead); Writing – review & editing (equal). Z. H. Cai: Data curation (equal); Formal analysis (supporting); Investigation (supporting); Methodology (equal); Software (equal); Validation (supporting); Visualization (equal); Writing – review & editing (supporting). J. Li: Conceptualization (lead); Formal analysis (equal); Funding acquisition (lead); Investigation (equal); Methodology (lead); Project administration (lead); Resources (lead); Software (supporting); Supervision (lead); Validation (equal); Visualization (supporting); Writing – original draft (supporting); Writing – review & editing (lead). C. Yao: Data curation (equal); Formal analysis (equal); Methodology (supporting); Software (supporting); Visualization (supporting); Writing – review & editing (supporting). L. Hao: Conceptualization (equal); Formal analysis (supporting); Methodology (equal); Project administration (equal); Supervision (supporting); Writing – review & editing (lead). F. X. Zhou: Data curation (equal); Methodology (equal); Software (equal); Supervision (supporting); Validation (supporting); Visualization (equal); Writing – review & editing (supporting). R. Yan: Conceptualization (lead); Formal analysis (equal); Funding acquisition (lead); Investigation (supporting); Methodology (equal); Project administration (lead); Resources (lead); Supervision (lead); Validation (equal); Writing – original draft (supporting); Writing – review & editing (lead). J. Zheng: Formal analysis (supporting); Funding acquisition (supporting); Project administration (equal); Resources (equal); Supervision (equal); Validation (supporting); Writing – review & editing (lead).
Author Contributions
All simulation and analysis data generated in this study were obtained using the high-performance computing platforms provided by the Hefei Advanced Computing Center. Due to restrictions imposed by computational resource usage policies, the raw data are retained by the author(s) and not publicly archived. Access to the data may be granted upon reasonable request through the first author or corresponding author.

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References(66)

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