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Gain of electron orbital angular momentum in a direct laser acceleration process
R Nuter1, Ph Korneev2,3, E Dmitriev2
1Université de Bordeaux, CNRS, CEA, UMR 5107, 33405 Talence, France.
Physical Review. E
|June 25, 2020
Summary
High-intensity lasers with orbital angular momentum (OAM) can transfer this OAM to plasma electrons, generating magnetic fields. This laser-to-electron OAM transfer is driven by ponderomotive forces and radial oscillations.
Area of Science:
- Plasma Physics
- Laser-Plasma Interactions
- Computational Electromagnetics
Background:
- Laguerre-Gauss beams possess orbital angular momentum (OAM), distinct from the axial momentum of Gaussian beams.
- Understanding laser-matter interactions is crucial for advanced energy and particle acceleration applications.
Purpose of the Study:
- To investigate the generation of quasistatic magnetic fields in plasma irradiated by Laguerre-Gauss beams.
- To analyze the transfer of orbital angular momentum from laser to plasma electrons.
Main Methods:
- Three-dimensional particle-in-cell (PIC) simulations were employed.
- Perturbative analysis of electron dynamics in the low-intensity limit was performed.
- Detailed numerical analysis was conducted to understand OAM transfer mechanisms.
Main Results:
- A quasistatic magnetic field is generated in plasma irradiated by a Laguerre-Gauss beam.
- A significant transfer of orbital angular momentum from the laser to plasma electrons was predicted.
- Plasma electrons gain angular velocity due to dephasing induced by ponderomotive force and laser-driven radial oscillations.
Conclusions:
- Laguerre-Gauss beams can effectively transfer their orbital angular momentum to plasma electrons.
- This OAM transfer mechanism is analogous to direct laser acceleration, but involves angular momentum.
- The findings have implications for novel particle acceleration and magnetic field generation techniques in plasmas.
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