I'm mostly interested about recombination not in plasma (e.g., recombination of beta particles with atoms that they pass by), although the rules are probably the same.
Say, there's a free electron and an atom. What determines whether they will recombine? Should the energy of the electron be below certain value for it to happen? Should it be at certain distance from the atom?
Also, how do those requirements differ for different atoms? Does recombination happen more readily with some atoms rather than others?
Also, electrons usually recombine with positive ions (that's what happens in plasma), but I know that they can also recombine with neutral atoms or even negatively charged ions. Why would an electron be captured by a negative atom, when they're supposed to be repelled?