Sublimation and Ion Pumping in Getter-Ion Pumps

A large variety of methods have been studied for evaporation and sublimation of titanium. For use in getter-ion pumps, sublimation appears to be clearly superior to evaporation from the molten state. A number of getter-ion pumps have been built and used for various applications. Each utilizes a plasma-containing grid as a source of electrons for heating titanium rods. The grid also provides the necessary ionization for the pumping of inert gases. Consideration is also given to effects of geometry, scaling, pressure, and recombination rates on ionization and pumping by the grid.