Modeling Kinetic Neutral Atoms in the Solar-Wind/Interstellar-Medium Interaction Region

摘要

The solar wind is a continuous stream of plasma flowing out from the Sun. The flow of interstellar medium plasma diverts the solar wind and creates a teardrop shaped heliosphere. Although the plasma flows do not mix, neutral atoms of interstellar origin penetrate deep into the solar wind, unhin-dered by magnetic field fields. Charge-exchange couples these neutral atoms to the ionized plasma, creating a complicated neutral atom distribution function which encapsulates aspects of the cold interstellar, fast solar wind and hot he-liosheath parent plasma populations. Due to the large mean free paths, we must model the neutral atoms kinetically. In this paper we will present an overview of the kinetic neutral atom model and its coupling to a 3D MHD-plasma code. We will indicate some key results regarding the neutral distribution function and how this compares to neutral fluid models. Finally we show how this model can be used to predict and understand energetic neutral atom skymaps which will be a key part of the upcoming IBEX mission data.