Authors: Evan P. Shimoun (University of Michigan), Susan T. Lepri (University of Michigan), Jim M. Raines (University of Michigan), Lynn B. Wilson (Goddard Space Flight Center)

Heavy element charge state properties, such as those of carbon and oxygen, measured in the solar wind can provide diagnostic information about the regions in the corona where they are formed and freeze-in. For both carbon and oxygen, this freeze-in distance is expected to be within 2 Rs and after this point the charge states should remain unchanged as they travel out into the heliosphere. The Heavy Ion Sensor on Solar Orbiter provides an opportunity to test the freeze-in theory within the inner heliosphere. We expect to find that the ionization states of carbon and oxygen remain constant with the radial distance. To verify this frozen-in state of the solar wind we examine O7/O6, C6/C5, and C6/C4 ratios from HIS. While we find that O7/O6 and C6/C5 remain consistent across the radial distances sampled as we expected, a non-constant increasing trend was observed in the C6/C4 ratio. As such, we are investigating these relationships further to explore the reason for this deviation and the potential implications for charge state ratio measurements in the heliosphere.