Hybrid Monte Carlo-fluid modeling network for an argon/hydrogen direct current glow discharge

摘要

A hybrid modeling network, consisting of several Monte Carlo and fluid models, is developed for a dc glow discharge typically used for mass spectrometry, in a mixture of Ar with 1% H_2. The species described in the model are: electrons; Ar~+ ions and fast Ar atoms; ArH~+, H~+, H_2~+ and H_3~+ ions; H atoms; and H_2 molecules; as well as Ar metastable atoms. Sixty-three reactions are taken into account in the model. The calculated densities of the various plasma species are presented. The electrons and Ar~+ ions are the dominant charged species in the plasma, with densities in the order of 10~(11) cm~(-3). Furthermore, the ArH~+ and H_3`+ ions have a relatively high density (in the order of a few 10~(10) cm~(-3)), whereas the H~+ and H_2~+ densities are negligible (order of 10~6-10~7 cm~(-3)). The dissociation degree of the H_2 molecules was calculated to be very low (approx. 0.02%), yielding H_2 and H densities in the order of 10~(14) and 10~(11) cm~(-3), respectively. The relative contribution of different production and loss processes of the electrons, different ions. H atoms, H_2 molecules and Ar metastable atoms are also calculated. Finally, a comparison is made between a pure Ar discharge and a glow discharge in a mixture of Ar + 1% H_2.