Experimental and numerical investigations of charging interactions of a dusty surface in space plasma

The objective of this dissertation is to study the charging interactions of a dusty surface in space plasma through experimental, analytical, and numerical investigations. Specifically, this dissertation investigates 1) dust charging on a dusty surface and 2) dust manipulation on a dusty surface.;In the first area, an analytically approximate capacitance model for a dusty plasma and dust layer using the capacitance matrix method and an averaged inter-dust distance to account for dust interactions, has been developed. In the previous studies, the single isolated dust charging model is a commonly used for dusty surface charging with the OML current collection model for potential calculation, and experiments conducted only measured the charge and charge to mass ratio for a single dust particle in plasma. Hence, the capacitance model of a dust on a dusty surface in plasma was still not understood. In our study, we first validated the capacitance model derived with experiment and then developed another experiment to measure the charging of JSC-1A dust layer in plasma inside a vacuum chamber. It is found that the single dust charging model is no longer applicable to packed dust charging on a dusty surface as it shows calculation results two orders of magnitude higher than the measurement because the interactions between surrounding dust particles were ignored. The dusty surface in plasma model developed assuming an averaged inter-dust distance approximation provides an accuracy of 50% to 60% compared with the measurement. This is found to be an accurate model to calculate the dust charging on a dusty surface immersed in plasma.;In the second area, we investigated the underlying physics of dust behavior in the surface electrostatic traveling wave on an electrodynamic screen (EDS) device using numerical computer simulations. Previous studies only demonstrated the application of removing dust particles accumulated on surfaces with three-phase or four-phase surface electrostatic traveling waves without concluding the physics of the dust dynamics in such traveling waves. We found that there are two cut-off frequencies of the wave as a function of dust charge to mass ratio; and a dust particle can only respond to a frequency between the higher and lower cut-off frequencies and follow the surface traveling wave to be transported. With the understanding of dust dynamics in the traveling waves, we also proposed a new design of an EDS device using multi-phase surface traveling waves to precisely control the dust motion. The capability of the new design includes dust mitigation, sorting and segregation on the lunar, Martian and asteroid surfaces according to the dust charge to mass ratio.