Formation of plasma around a small meteoroid: 2. Implications for radar   head echo
  This paper calculates the spatial distribution of the plasma responsible for radar head echoes by applying the kinetic theory developed in the companion paper (Dimant and Oppenheim, arXiv:1608.08524). This results in a set of analytic expressions for the plasma density as a function of distance from the meteoroid. It shows that, at distances less than a collisional mean-free-path from the meteoroid surface, the plasma density drops in proportion to $1/R$ where $R$ is the distance from the meteoroid center; and, at distances much longer than the mean-free-path behind the meteoroid, the density diminishes at a rate proportional to $1/R^{2}$. The results of this paper should be used for modeling and analysis of radar head echoes. 
Y. S. Dimant and M. M. Oppenheim
physics.plasm-ph