Direct Laser Acceleration in Underdense Plasmas with Multi-PW Lasers: A Path to High-Charge, GeV-Class Electron...

Area of Science:

• Plasma physics
• Laser-driven particle acceleration

Background:

• Direct laser acceleration (DLA) in underdense plasmas offers a pathway to high-energy electron beams.
• Current laser technology enables the acceleration of hundreds of nanocoulombs of electrons to near-gigaelectronvolt energies.

Purpose of the Study:

• To demonstrate the critical role of electron transverse displacement in DLA.
• To develop an analytical model for predicting maximum electron energies in DLA.
• To present a strategy for optimizing DLA using matched laser focusing.

Main Methods:

• Analytical modeling of electron transverse displacement effects.
• Quasi-3D particle-in-cell simulations of laser pulse propagation in a plasma channel.
• Parametric studies across various plasma densities and laser intensities.

Main Results:

• Electron transverse displacement significantly influences acceleration efficiency.
• Analytical predictions of maximum electron energies show agreement with simulation results.
• Achieved electron energies exceed 10 GeV for laser intensities around 10^21 W/cm^2.

Conclusions:

• Electron transverse displacement is a crucial factor for optimizing direct laser acceleration.
• The developed analytical model provides a tool for predicting and optimizing DLA performance.
• Matched laser focusing strategies enable access to multi-gigaelectronvolt electron energies in near-future laser facilities.