Shocks in the interplanetary medium ahead of Coronal Mass Ejections (CMEs) can accelerate solar wind plasma to high energies. Ions heavier than protons can be used as tracers for the associated heating and acceleration mechanisms in the solar wind plasma.
Helium, as measured by the ACE and Wind satellites, is studied in a series of quasi-perpendicular shocks associated with CMEs from 1997-2012. The heating seen in helium after the shock passage is compared to the proton heating in the each shock. The orientation of the shock normal to the magnetic field is also examined, as the structure of the shock can be oriented differently from one spacecraft to the next possibly explaining the variations in heating. The scale of change of the magnetic orientation of the shock angle as a proxy for the structure of the shock and its influence on heating is discussed.