Compound ion distributions, fi(v), have been measured with high-time resolution by NASA's Magnetospheric Multi-Scale Mission (MMS) and found in reconnection simulations. A compound distribution, consisting, for example, of essentially disjoint pieces will be called a multi-beam distribution modeled as sum “beams,” fi(v) = f1(v) + ? fN(v). Velocity moments are taken beam summed. Such advantages ...