The evidence for supernova remnants as the main sources for Galactic cosmic rays has
accumulated over the past decades. However, the physics of the acceleration mechanism
is still unclear. In particular, there is a lack of empirical data to test current
shock acceleration models.

RCW 86 is an excellent source to test these models, as the shock velocities of the
remnant vary by an order of magnitude and parts of the remnant have shown to be
efficient accelerators. I will present our study of this remnant, thereby focusing on
differences of the electron and proton temperatures behind the shock fronts and on
measuring proper motions of various parts remnant. I will discuss these results in
the context of cosmic-ray acceleration models.