ION-ELECTRON AND ION-NEUTRAL COLLISIONS IN ION TRAPS

Studies of gas-phase collisions of atomic particles have been driven largely by modelling and diagnostic needs of natural and laboratory plasmas and by a search for fundamental understanding. Ion traps of many varieties have been employed for a plethora of studies and have made possible investigations into some areas which are not accessible by other means. Various trapping schemes are mentioned and associated with the particular collisions areas where they are most effective. Collisions measurements in high-order electric multipole traps, in ion-storage rings, and in electron-beam ion trap/source (EBIT/EBIS) devices now occupy a prominent role in collisions work. They are discussed in the context of the spectrum of traps and studies done, but not in detail, since other papers in this issue are devoted specifically to them. Thus, after surveying the diversity of traps and collisions types for which they are used, the remainder of the paper is directed to an examination in more detail of the remaining trapping methods and collision measurements.