Kinetic properties of heavy solar wind ions from Ulysses‐SWICS

The kinetic properties of heavy ions in the solar wind reflect the plasma processes governing the solar wind in the heliosphere. We use Ulysses‐SWICS data that resolve heavy ions in a wide range of mass‐per‐charge values, 2 ≤ m / q ≤ 9.33, to investigate the heavy ions and their dynamic evolution throughout the heliosphere. While at 1 AU the imprint of Coulomb collisions is known to be present in the slow solar wind, we show that is vanishes by the time the wind has reached 5 AU. All ion species flow with equal bulk and thermal speeds there. This is interpreted as a progressive dominance of wave‐particle interactions over Coulomb collisions.