Dust-Alfvén Mach Cones in Saturn's Dense Rings

The formation of Mach cones associated with dust-Alfvén waves in Saturn's dense rings has been theoretically investigated. It is explicitly shown that for typical dusty plasma parameters corresponding to Saturn's dense rings, Mach cones are only formed by dust-Alfvén waves which are found to be more prominent than any other longitudinal waves (e.g. dust-acoustic waves). The characteristics of the dust-Alfvén Mach cones that are found to be formed in Saturn's dense rings are also presented. The dusty plasma model, dust-Alfvén waves, and dust-Alfvén Mach cones that we predict in our present letter are expected to be observed in Saturn's dense rings by the imaging and occultation experiments on board the NASA/ESA space mission CASSINI, arriving at Saturn in 2004.