Spectral Study of Glow Discharge with Dusty Structures

TL;DR

This study investigates how dusty structures influence glow discharges in neon and argon, revealing significant effects on radiation distribution and electron temperature, using optical spectroscopy and fluorescence techniques.

Contribution

It provides experimental insights into the impact of dust particles on plasma properties, highlighting the formation of structures and their effects on spectral emissions.

Findings

Large dust structures cause redistribution of radiation in argon discharges.

Spectral lines weaken by 9-50% at the tube center with dust formation.

Electron temperature increases near the tube wall due to dust-related effects.

Abstract

We present the results of the experimental study of the influence of dusty structures on plasma. We have studied glow discharges in neon and argon with $\text{Al}_2 \text{O}_3$ polydisperse particles and melamine-formaldehyde monodisperse particles with the diameter of $\text{4.83} \; \mu m$. We used optical emission spectroscopy and laser-induced fluorescence methods to measure shift of excited atoms populations, which led to similar results. In most cases, the population change was negligible as compared to the inaccuracy. $\text{Al}_2 \text{O}_3$ particles in argon formed large structures which caused dramatic redistribution of radiation. In this case, spectral lines and fluorescence became 9-50% weaker at the tube center after dusty structure formation. It might be accounted for by a decrease of electron density due to recombination on the surfaces of the particles. Near the tube wall, the radiation became brighter due to an electron temperature increase. Photographs of the discharge allowed us to calculate the radial distribution of the population shift.