Numerical simulation of radial plasma transport in the saturn's magnetosphere

This paper constructs a self-consistent stationary model of the Saturn s magnetosphere, in which the centrifugal force is included. Based on the thin-filament model, numerical simulation of radial plasma transport in the Saturn's magnetosphere is carried out. The results show that the plasma near Dione may be transported to the farther place because of the centrifugal interchange instability. This type of transportation is dominated by the centrifugal force, the viscidity and energy transfer do little on the transportation (almost negligible) but the ionospheric conductance has important influence. Lower value of conductance causes faster transportation while higher value of conductance will block transportation to some extent. The plasma near Dione (6.3R_s from the Saturn) has been transported to 10R_s from the Saturn in 5.52 hours when the ionospheric conductance is set to 2 S. Our simulations also show that the plasma is unstable if the density is disturbed, when the Lorentz force and the gradient of plasma thermal pressure can not balance with the centrifugal force, radial transportation will happen. The radial plasma transport in the Saturn's magnetosphere is that the denser plasma becomes cooler because of adiabatic expansion in the process of outward transport while the injected lighter plasma becomes hotter due to the adiabatic compression.