HR: 09:30h
AN: SM11B-07    [PDF]
TI: Pickup ions, plasma anisotropy and instability at Saturn: Predictions for Cassini
AU: * Crary, F J
EM: fcrary@swri.edu
AF: Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228 United States
AU: Young, D T
EM: dyoung@swri.edu
AF: Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228 United States
AB: Pickup ions are a primary source of plasma within Saturn's magnetosphere. These ions are initially in a strongly anisotropic ring distribution, but instabilities can rapidly cause them to evolve into a more isotropic distribution. Similar processes have been studied at length in the case of comets and Jupiter's moon, Io. Here, we apply these theories to Saturn's magnetosphere and predict that the Cassini spacecraft will frequently observe strongly anisotropic distributions. The important processes are the suppression of the ion cyclotron instability by a thermal background of a similar species, the limits to which ion cyclotron waves may reduce anisotropy (especially in a plasma where the pickup velocity is lower than the wave velocity) and the stability criteria for mirror mode instabilities.
DE: 2752 MHD waves and instabilities
DE: 2772 Plasma waves and instabilities
DE: 5737 Magnetospheres (2756)
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting