Title: SPATIAL AND TEMPORAL VARIATIONS OF THE SUPRATHERMAL (3-220 KEV/E) ION COMPOSITION IN SATURN’S EQUATORIAL MAGNETOSPHERE

We have studied the composition of the suprathermal ions (3-220 keV/e) in Saturn’s magnetosphere using data from the Charge-Energy-Mass Spectrometer (CHEMS) on the Cassini Saturn orbiter from 78 equatorial (Latitude =-10 ° to 10°) passes during the period 2004-2010. We use this data to determine how the suprathermal ion density and composition vary with time, energy, and distance from Saturn (L-shell). This information is used to study the relative importance of various sources of plasma and neutral particles and how they may vary with time. We also examine the loss and energization processes of the suprathermal ions. In Saturn’s main ring current region (L=7-16), we find that the suprathermal ion composition is 63 % W (