Ion reflection, gyration, and dissipation at supercritical shocks

Topics on collisionless plasmas are discussed and include: (1) Ion reflection is the dominant ion dissipation mechanism at nearly perpendicular, supercritical shocks. (2) An increasing fraction of the ions incident on a supercritical shock is reflected as the Mach number increases. The actual fraction reflected can be predicted using the Rankine Huqoniot conservation relations. (3) The effective temperature associated with the dispersion in velocity space associated with ion reflection accounts for a large fraction of the temperature rise observed across supercritical, quasi perpendicular shocks.