Electron-impact ionization cross section is a measure of the probability of an incident electron colliding with an atom or molecule and causing it to lose one or more electrons, resulting in ionization.
Electron-impact ionization cross section is typically measured through experiments in which the cross section is determined by comparing the number of atoms or molecules ionized by an electron beam with the total number of collisions that occur.
The cross section is influenced by a variety of factors such as the energy of the incident electron, the target atom or molecule, and the angle of collision.
Electron-impact ionization cross section is important in understanding and predicting the behavior of atoms and molecules in various environments, such as in plasma or in the Earth's upper atmosphere. It is also used in fields such as astrophysics, where it helps to explain phenomena in outer space.
Electron-impact ionization cross section differs from other ionization processes, such as photoionization or collisional ionization, in that it involves an electron colliding with the atom or molecule rather than being absorbed by it. It also typically results in multiple ionization events, where more than one electron is ejected from the target.