Pitch angle distributions of energetic electrons at Saturn

Pitch angle distributions of energetic electrons (110-365 keV) at Saturn are statistically analyzed for 2005-2009. Using a nondipolar model magnetic field, pitch angle distributions are mapped to the magnetospheric equator and sorted by equatorial crossing distance. The results are quantified using a standard function for the pitch angle distribution, f(alpha) = Asin(alpha)(kappa) (where alpha is the pitch angle and K is the power). Inside of similar to 10 R-S, the distributions are mostly peaked at 90 degrees (K < 0), signifying a trapping distribution. Outside of this distance, the distributions are mostly field aligned (K > 0) with maxima near 0 degrees and 180 degrees. The 10 RS boundary maps to Saturn's ionosphere at latitudes equatorward of the aurora. Very few flat distributions are observed (K approximate to 0). The pitch angle distributions are not as well organized in local time as they are in radial distance, but over the 5 year survey between 10 and 20 R-S field-aligned distributions appear most often near midnight, while trapping distributions are found elsewhere.