| dc.description.abstract | The objective of my thesis research aims to study the evolution and physical implications of the orbital motion of charged dust grains with different charge-to-mass ratios (Q/m) in the vicinity of the Saturnian rings. By the way,
the number density distributions of charged dust grains with different Q/m could also be acquired via numerical simulations. In this research, I used the Runge-Kutta 4th order method and which with some concepts from the Monte
Carlo method to calculate the trajectories and number densities of the charged dust grains, respectively. The charge was fixed for all the orbital motion. However, I also tested the trajectories and number densities of charged dust
grains affected by the shadow effect, and the charge properties of charged dust grains would be different instead of fixed. According to the results, when Q/m≥10^-4 e/mP, charged dust grains would precipitate into the upper atmosphere of Saturn via siphon flow if the injected positions of which were smaller than the stability critical radius (rc=1.53 RS). Besides, perhaps the ionosphere depletion of Saturnian equator was due to the injection of charged dust grains which with Q/m between 10^-6–10^-7 e/mP, and this phenomenon was observed via the Cassini radio occultation measurements. Furthermore, if charged dust grains did the orbital motion with the shadow effect, then something was different from purely positively or negatively charged dust grains did. The trajectories of charged dust
grains within the Encke Gap could provide the information about the orbital stability via the relation between Q/m and angular velocity. However, there has not been in-situ observation near the ring plane until now, so this research work not only provides the cornerstone for the future observational model but also interprets some phenomena which happened to the upper atmosphere of Saturn, Saturnian ring system, and the interaction between Saturnian ring system and Saturn. | en_US |