# estimating ion collisions from Vlasov equations

Suppose you have a distribution function $f_{\alpha}( \vec{r} , \vec{p} , t)$ obtained from Vlasov equations for a certain $\alpha$ species, say some ions.

Is there a rigorous way (in the domain of validity of the model, that is) to estimate a collision density function $p^{collisions}_{\alpha}( \vec{r} , E_{CM} , t)$ , where $E_{CM}$ is a variable describing collision energy parameters? A link or reference would be great

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