Imaging ion outflow in the high-latitude magnetosphere using low-energy neutral atoms

The measurement of neutral atom fluxes generated by charge exchange with the Earth's geocorona has recently been shown to provide the capability to image the magnetosphere. We investigate neutral oxygen fluxes produced by charge exchange from the cusp/cleft ion fountain population. Using an empirical cusp/cleft ion fountain model, an empirical variation of the geocoronal neutral hydrogen density with distance, and typical values for charge-exchange cross sections, line-of-sight integrations are performed to calculate the neutral oxygen flux at arbitrary locations in space. The resulting images are evaluated for a set of orbital positions of the proposed HI-LITE small explorer spacecraft. The resulting neutral oxygen fluxes are high enough for imaging with a low-energy neutral atom imaging instrument (ILENA) onboard the spacecraft.