Kinetic properties of heavy solar wind ions from Ulysses-SWICS

Abstract

The kinetic properties of heavy ions in the solar wind reflect the microphysical processes governing the solar wind in the heliosphere. We use the unique data set of Ulysses-SWICS which provides data in a wide rage of mass per charge, 2 ≤ m/q ≤ 9.33. In particular, we look for slight deviations from the canonical behaviour of equal bulk speed and equal thermal speed of all heavy ion species. Such deviations are expected to carry signatures of the wave-particle interaction processes in the solar wind, and to a lesser extent, to collisions which tend to bring the particles closer to thermal equilibrium. The data set of Ulysses-SWICS is ideal for this task because it spans not only a large range in m/q, but also in time, solar wind speed (covering extended time periods in slow and in fast wind), heliographic latitude, and heliocentric distance.