An explanation for the lack of ion cyclotron wave generation by pickup ions at Titan: 1‐D hybrid simulation results

[1] Titan’s dense atmosphere is thought to be an important source of pickup ions in the Saturnian magnetosphere. Cassini spacecraft measurements of the plasmas near Titan show evidence of pickup ions, yet electromagnetic ion cyclotron waves, which are direct indicators of ion pickup, have not yet been detected. Pickup ions and their associated ion cyclotron waves have been observed at Saturn’s Extended Neutral Cloud (∼4–10 Rs), as well as at Jupiter’s moon, Io, suggesting that the plasma and pickup conditions near Titan may be fundamentally different than these other environments. Using 1‐D hybrid simulations, we investigate ion cyclotron wave growth for variable conditions in the Titan environment to test which conditions could yield waves with sufficient amplitude to be clearly detected by spacecraft. Results suggest that ion cyclotron waves have not been observed at Titan because their growth time is too long compared to the convection time of background plasma through the interaction region and therefore will not be of sufficient amplitude to be observed by Cassini. Because Titan can be located in either the magnetically noisy Saturnian current sheet or in the magnetically quiet lobe region, we consider both of these environments in this study.