Ion Acceleration in Quasi-Perpendicular Shocks: Observations from MMS

We analyze the ion acceleration and reflection processes in a small set of shock observations by MMS. The burst-rate ion distributions upstream are subdivided into the incident solar wind beam and a population of reflected and/or accelerated ions ahead of the ramp. Ion moments may be calculated separately for each of these populations, yielding solar wind moments near the shock that are not influenced by the reflected particles. We offer an interpretation of possible acceleration mechanisms based on the time-series of ion density at different energies and on the energy profiles at different times in the vicinity of the shock ramp.