Analysis of dust charge fluctuations with double-ionized ions and plasma oscillations / instabilities in Hall thrusters

In an electric propulsion system such as thruster, dust particles are generated because of the thrusters' wall erosion, and these heavily charged dust particles affect the thrusters' performance and life span. In this article, the charge and potential of a dust grain for various dust and plasma parameters are analyzed in a Hall thruster plasma having high electron thermal energy in the presence of double-ionized ions. The charging time of the dust is shown to be reduced with the increase in size while the charge on it increases. This has been observed that the dust grains' charging time and floating potential decrease when the density of double-ionized ions is increased. An increment in the floating potential is observed for higher plasma potential and electron temperature, but this increment occurs slower for higher electron temperatures. The floating potential doesn't change with the size of the dust in the plasma with zero fluctuations, but it depends on the dust grain size for fluctuating plasma parameters and the frequency of these fluctuations.