Laser-heater assisted plasma channel formation in capillary discharge waveguides

TL;DR

This paper introduces a novel method to create controllable plasma channels in capillary discharge waveguides using a laser heater, enabling better guiding of high-power laser pulses for electron acceleration.

Contribution

The study demonstrates a new technique combining laser heating with capillary discharge to produce deeper, more controllable plasma channels for laser guiding.

Findings

Laser heating modifies plasma channel depth and profile.

Deeper plasma channels enable smaller laser spot sizes.

Method improves electron acceleration efficiency.

Abstract

A method of creating plasma channels with controllable depth and transverse profile for the guiding of short, high power laser pulses for efficient electron acceleration is proposed. The plasma channel produced by the hydrogen-filled capillary discharge waveguide is modified by a ns-scale laser pulse, which heats the electrons near the capillary axis. This interaction creates a deeper plasma channel within the capillary discharge that evolves on a ns-time scale, allowing laser beams with smaller spot sizes than would otherwise be possible in the unmodified capillary discharge.