What is the difference between "Gas Phase Ion Chemistry" and "Plasma Chemistry"? If one wants to learn about the ionization and dissociation processes of hydrogen gas are either of theses fields appropriate to study?
I think that, by its definition, the plasma phase implies some degree of ionization.
Therefore the temperature must be high enough to reach a sufficient ionization level.
Ionization and dissociation are therefore more important in a plasma than in a "normal" gas.
However, even at "ambient" temperature, there is some ionization.
In addition, ionization can be obtained by other means that high temperatures: like by exposition to radiations (UV for example).
You will find a lot of data about ionization equilibrium in plasma physics.
See for example the Saha equation:
I've read that "Plasmas are gas phase systems". So are "Gas Phase Ion Chemistry" and "Plasma Chemistry" different names for the same field? Is this an appropriate field to study in order to learn about the dissociative ionization of hydrogen gas?