Injection and Acceleration of Electrons by Radially Polarized Laser Pulses in a Plasma Channel

TL;DR

This study demonstrates that radially polarized laser pulses in plasma channels enhance electron injection and acceleration, with polarization and focusing geometry being crucial for optimizing laser-driven electron acceleration.

Contribution

It shows that radially polarized laser pulses significantly improve electron injection and acceleration in plasma channels compared to linearly polarized pulses, highlighting the importance of polarization and focusing geometry.

Findings

Radially polarized pulses increase electron injection efficiency.

Tighter focusing with radially polarized pulses yields higher electron energies.

Radially polarized f/10 pulses inject about one-third more charge than linearly polarized ones.

Abstract

We consider injection and subsequent acceleration of electrons in narrow plasma channels irradiated by linearly and radially polarized ultraintense laser pulses. Using three-dimensional particle-in-cell simulations, we show that radially polarized beams significantly promote electron release from the channel walls and lead to enhanced injection. We compare an f/10 linearly polarized laser beam with two radially polarized cases: one focused more tightly (f/5) to match peak intensity, and one at equal f/10 to capture polarization effects. The radially polarized f/10 case injects approximately one-third more charge than the linearly polarized case, while the f/5 radially polarized case outperforms the linearly polarized one by about a factor of two in terms of maximum electron energy. These results highlight polarization and focusing geometry as key parameters for optimizing laser-driven electron acceleration setups.