Structure functions and pair-correlation in space plasma physics

Structure functions account for the microscale interparticle distributions of second order, that is, correlation between pairs of electrons or ions. Ordinarily in space plasmas physics one considers only the first order particle distributions when discussing pitch angle distributions, velocity distributions, and similar constructs. However numerous important physical aspects are only to be found in higher order distributions. Most importantly the pair-correlation function includes the effect of particle pair interactions in contrast to collective plasma effects. This work presents Monte-Carlo simulations and measurements for the purpose of obtaining pair correlation functions for typical space plasmas around the Earth. In particular the work is based on the DWP electron correlator on the CLUSTER satellite mission.