Dust release from surfaces exposed to plasma

Abstract

Micrometer-sized particles adhered to a surface can be released when exposed to plasma. In an experiment with a glass surface coated with lunar-simulant dust, it was found that particle release requires exposure to both plasma and an electron beam. The dust release rate diminishes almost exponentially in time, which is consistent with a random process. As proposed here, charges of particles adhered to the surface fluctuate. These charges experience a fluctuating electric force that occasionally overcomes the adhesive van der Waals force, causing particle release. The release rate increases with plasma density, so that plasma cleaning is feasible at high plasma densities. Applications of this cleaning include controlling particulate contamination in semiconductor manufacturing, dust mitigation in the exploration of the moon and Mars, and dusty plasmas.

The effect of surface topography on the lunar photoelectron sheath and electrostatic dust transport

“…Over time, these models have become progressively more complex and realistic in their description of both the plasma environment around airless bodies and their treatment of dust grain motion; however, open questions still remain, including the role of both topography, such as craters or boulders, and varying solar zenith angle in modifying the near-surface plasma environment, the influence that complex electric fields near craters and boulders have on the electrostatic transport of dust grains, and the ability of craters to accumulate dust grains via electrostatic transport over long periods of time. Laboratory work has confirmed some aspects of the theory of electrostatic dust transport, including the ability to charge and levitate dust grains in a plasma sheath (Sickafoose et al, 2001(Sickafoose et al, , 2002Robertson et al, 2003;Flanagan and Goree, 2006;Wang et al, 2009), the presence of elevated electric fields near differentially charged surfaces (Wang et al, 2007), and the electrostatic transport of dust grains near an electron beam impact/shadow boundary (Wang et al, 2010(Wang et al, , 2011.…”

Triboelectric and plasma charging of microparticles

“…Other estimates in literature assume that the particle acquires a similar surface charge density to the surface [17,16,18]. This is the true when the particle is conductively connected to the surface.…”

“…gested that the charge fluctuations may be important [17]. Sheridan and Hayes [16] have derived an expression for the RMS charge (dotted line in figure 7).…”

Background Subtraction for the SECCHI/COR1 Telescope Aboard STEREO

“…Monitoring of star brightnesses shows that this drift is an actual decrease in the scattered light levels, and not a change in the instrument sensitivity. We believe that the objective lenses are slowly cleaning themselves of contaminants, possibly through a process known as plasma cleaning (Flanagan and Goree, 2006). Indeed, there was a significant drop of about 15% in the scattered light levels for both COR1 telescopes within a few days after the instrument doors were first opened in December 2006.…”