Modeling of Pickup Ion Distributions in the Halley Cometo-Sheath: Empirical Rates of Ionization, Diffusion, Loss and Creation of Fast Neutral Atoms

Abstract

The shape of the velocity distribution of water-group ions observed by the Giotto ion mass spectrometer on its approach to comet Halley is modeled to derive empirical values for the rates on ionization, energy diffusion, and loss in the mid-cometosheath.