Study of Photoemissive Dusty Plasma

Abstract

The present work deals with the experimental and theoretical investigation of photoemissive charging of polydisperse dust particles. The characteristic size of dust particles under consideration was 0.1–25 mkm. The experimental part of this work was devoted to the study of positive charging of macroparticles under UV‐radiation that acted on dusty formations. Investigations were carried out in argon at normal pressure with particles of different materials. Dust structure was subjected to radiation. The power and frequency spectrum of this radiation was close to corresponding parameters of sun radiation near the top layers of Earth atmosphere. Owing to electron photoemission the macroparticles became positively charged. On the basis of experimental data the estimation of this charge was performed. It was about 500 elementary charges for micron particles. The theoretical part of present work included the numerical simulation of photoemissive dusty plasma decay in a drift‐diffusion approximation. The model included equilibrium equation for positively charged macroparticles (in experiment, the percent of these particles was about 90), negatively charged dust particles (about 10%), positive ions (those were born by electron strike of buffered gas atoms) and electrons. Also the model included the Poisson equation for determination of potential distribution in the discharge region. The results of numerical calculations were in a satisfactory correspondence with experimental data both for time dependences of positively and negatively charged macroparticles concentrations and for their velocities.The present work deals with the experimental and theoretical investigation of photoemissive charging of polydisperse dust particles. The characteristic size of dust particles under consideration was 0.1–25 mkm. The experimental part of this work was devoted to the study of positive charging of macroparticles under UV‐radiation that acted on dusty formations. Investigations were carried out in argon at normal pressure with particles of different materials. Dust structure was subjected to radiation. The power and frequency spectrum of this radiation was close to corresponding parameters of sun radiation near the top layers of Earth atmosphere. Owing to electron photoemission the macroparticles became positively charged. On the basis of experimental data the estimation of this charge was performed. It was about 500 elementary charges for micron particles. The theoretical part of present work included the numerical simulation of photoemissive dusty plasma decay in a drift‐diffusion approximation. The model in...