Electron Collisions with Molecular Ions

In the present chapter, an electron collision with positive molecular ions is considered. If ignoring negative ions, the density of ions is equal to the electron density. Since the electron density is much smaller than the density of neutral molecules in most of molecular plasmas, the electron collision with ions is much less frequent than the electron collision with molecules. Accordingly the electron–ion collisions are less important in molecular plasmas. Furthermore it is difficult to do any experiment of electron–ion collisions, because ions cannot be accumulated enough to serve as the collision target. In fact, very few experimental data are available for the electron–ion collisions. One exception is the electron–ion recombination. It is separately described in Sect. 7.2.