PLASMA POPULATIONS. “It is important to note that the dynamic processes all occur on time scales that are short compared to collision times, which means that the plasma populations can retain their characteristics without being thermalized, and that the plasma distribution functions can significantly deviate from simple Maxwellians. Figure 4 shows the key plasma populations in the magnetosphere.”
https://link.springer.com/article/10.12942/lrsp-2007-1