Position dependent microparticle charge in a spatiotemporal afterglow plasma

Abstract

In the growing field of dusty afterglow plasma physics, the key parameter is the residual charge of dust particles. However, the particle (de)-charging process in afterglow plasmas is still far from fully understood and further development of a governing theoretical framework requires experimental data. In this work, the influence of the location of a microparticle in a spatiotemporal afterglow plasma, at the moment when the plasma was terminated, on its residual charge is investigated. It is found that the measured charge depends strongly on the local characteristic diffusion length scale of the system, while the plasma power prior to the start of the temporal afterglow phase is of much less influence. Our results contribute to an improved understanding of particle (de)-charging in afterglow plasmas and are highly relevant to the design of applications in which afterglow plasmas are present and where the charge of dust particles needs be controlled for the sake of (nano)contamination control.