Inter-Calibration of Solar Orbiter’s Heavy Ion Sensor and Suprathermal Ion Spectrograph

The distribution of charged particles in the heliosphere covers more than 16 orders of magnitude in particle flux and more than 6 orders of magnitude in energy. While the majority of these particles are ionized hydrogen (protons) and fully ionized helium (alpha particles), heavier ions are also present. Because of the large parameter space that must be covered, different instruments are required and these instruments must be optimized to specific energy and particle flux ranges. They must also be designed to target specific ion species. To properly characterize the means by which different energy ranges are populated, the observations from these different instruments must be intercalibrated.

We present initial progress intercalibrating observations from Solar Orbiter’s Heavy Ion Sensor (HIS) and Suprathermal Ion Spectrograph (SIS). HIS is a heavy ion composition experiment that targets the solar wind through the low energy range of suprathermal energies with mass and charge state resolution. SIS covers the suprathermal and low range energetic particles with high mass resolution but without charge state resolution. Together, these two sensors cover heavy ion composition from solar wind to suprathermal energies. During advantageous conditions, proton distributions across both instruments are also available. Properly intercalibrated observations across these instruments enable studies of charged particle energization across the energy ranges, which is essential for characterizing a wide range of phenomena in heliosphere.