ABSTRACT
Electrons stick to such molecules or collide with them with the formation of negative ions, the third important group of charged particles in plasmas. The concentration of negative ions can exceed those of electrons in electronegative gases. Electron attachment to atoms or molecules results in the formation of negative ions. Ionization of atoms and molecules by electron impact, electron attachment to atoms or molecules, and ion-molecular reactions are examples of elementary plasma-chemical processes, reactive collisions accompanied by the transformation of elementary plasma particles. The ionization in this case can be more homogeneous and provide a generation of uniform nonthermal plasmas even in atmospheric pressure systems. The electron beams can be also effectively combined with the electric field in non-self-sustained discharges, where electron beams providing ionization, and the energy consumption is mostly due to the electric field. An electron with kinetic energy slightly exceeding the ionization potential is quite effective to perform the ionization act.
