Effects of Titan's Induced Magnetosphere on ENA Production

Titan possesses an extensive atmosphere and ionosphere that interact directly with the surrounding plasma environment (usually Saturn's magnetospheric plasma) forming an induced magnetosphere. Energetic Neutral Atoms (ENAs) are formed during this interaction when singly charged magnetospheric ions collide with exospheric neutral atoms and undergo charge-exchange. The energy of the incident ions is almost entirely transferred to the charge exchange produced ENAs, which then propagate along nearly rectilinear ballistic trajectories. ENA images are used to remotely sense the ion fluxes and spectra at the time of the charge exchange collision. They also give information about the magnetic field in the vicinity of Titan and thus to Titan's interaction with the magnetosphere of Saturn. We perform Monte Carlo test-particle simulations using the electric and magnetic fields from a 3-d MHD simulation of Titan's interaction to study the effects that Titan's induced magnetosphere has on the source region of ENAs. We examine the resulting location of ENA production and the corresponding fluxes that the Cassini spacecraft may observe. We also compare ENA results for different exospheric models.