C.3.2 The electrostatic potential

In quasistatic conditions the ion and electron densities and , and the electrostatic potential V satisfy Poisson’s equation,

where the dielectric constant in vacuum. and the electron charge.

In vacuum the electrostatic potential, V, from an isolated punctual charge, , is given by

where is the distance from the charge. It is seen that the potential falls as 1/r in this case.