Collisional ionization
= Collisional ionization
{title2=$A+e^-\to A^++2e^-$}
In <collisional ionization>, an energetic collision frees a bound <Electron>. The process consumes kinetic energy and changes the <Electron> and ion populations controlling plasma cooling. In a thermal gas its rate competes with recombination and depends strongly on the <ionization> threshold relative to temperature.