Ion kinetics in a magnetized plasma source

There are regimes of plasma source operation in which the ion motion is controlled by the ambipolar electric field and ion–atom collisions. This paper presents a derivation of the corresponding ion distribution function and plasma density profiles in the source for a given electron temperature and a given gas ionization rate. Conditions are discussed under which the ion flux is predominantly radial or predominantly axial. It is found that the presence of plasma can substantially change the neutral gas pressure due to production of fast charge–exchange neutrals.