# Plasma Equilibrium inside Various Cross-Section Capillary Discharges

## TL;DR

This study models plasma behavior inside hydrogen-filled capillary discharges of different shapes, revealing that square cross-sections can effectively guide circular laser beams with minimal impact on electron beam symmetry.

## Contribution

It introduces dissipative magnetohydrodynamic simulations to analyze plasma properties in circular and square capillaries, demonstrating the viability of square capillaries for laser guiding.

## Key findings

- Similar plasma and temperature profiles in circular and square capillaries during quasistationary stage
- Square capillaries can guide circularly-symmetric laser beams effectively
- Minor effects on electron beam symmetry in square capillaries

## Abstract

Plasma properties inside a hydrogen-filled capillary discharge waveguide were modeled with dissipative magnetohydrodynamic simulations to enable analysis of capillaries of circular and square cross-sections implying that square capillaries can be used to guide circularly-symmetric laser beams. When the quasistationary stage of the discharge is reached, the plasma and temperature in the vicinity of the capillary axis has almost the same profile for both the circular and square capillaries. The effect of cross-section on the electron beam focusing properties were studied using the simulation-derived magnetic field map. Particle tracking simulations showed only slight effects on the electron beam symmetry in the horizontal and diagonal directions for square capillary.