Quasineutrality
= Quasineutrality
{title2=$\sum_s q_s n_s\simeq0$}
On spatial scales much larger than the <Debye length>, a <plasma> may have nearly cancelling positive and negative <electric charge> densities while still carrying an <electric current> and having a nonzero <electric field>. Quasineutrality is an approximation on appropriate slow macroscopic scales, not an assertion that each fluid element has exactly zero charge or that charge separation can be ignored at every boundary.