Self-consistent numerical simulations of RF dusty plasma afterglows, with and without plasma pulsing

Summary form only given. Plasma pulsing is potentially a powerful tool for controlling the properties of nanoparticles that nucleate and grow in nonthermal plasmas. Numerical simulations were conducted of a capacitively-coupled RF argon-silane dusty plasma (frequency 13.56 MHz, voltage amplitude 55 V, pressure 17 Pa, electrode gap 4 cm). The simulations used a previously reported 1D fluid model, [Warthesen, S.J., et al., 2007; Ravi, L., et al., 2009] in which the plasma equations and the aerosol general dynamics equation are selfconsistently coupled. Effects considered include particle charging by electron and ion attachment, particle coagulation, and particle transport by gas drag, ion drag, electrostatic force, gravity and Brownian diffusion. Profiles of particle nucleation and particle surface growth are treated as input parameters. Simulations consider cases both with and without gas flow through a showerhead electrode. Simulation results show that the behavior of the system during the afterglow is a consequence of the different time scales for particle charging, diffusion of electrons, ions and nanoparticles, particle coagulation and gas drag, together with the initial conditions at the time of plasma switch-off. Even with the applied electric field turned off, the existence of charge carriers in the afterglow affects the system´s evolution via Poisson´s equation. By controlling the time that nanoparticles grow before pulsing begins, and then tuning the pulse frequency and duty cycle, one can manipulate the properties of the nanoparticles and/or the plasma.