A theoretical study of steady-state properties of a high-current hydrogen discharge

A theoretical analysis of a highcurrent, medium-pressure ( about 1/2 Torr) hydrogen discharge during the steady-state phase is presented. The electron density in the plasma is equal to 1014 cm-3 and the electric field is of the order of 10 V/cm. Conditions considered are typical of some thyratrons and plasma switches. The electron temperature and drift velocity are determined, and conditions for the existence of a Maxwellian electron distribution function are analyzed. It is shown that the role of electron-electron collisions is important in the discharge and that these collisions keep the electron distribution in the steady state close to a Maxwellian form. Plasma transport coefficients such as electron diffusion, mobility and conductivity are calculated. Taking into account the contribution of coulomb collisions causes the plasma transport coefficients to differ by about a half order of magnitude from the values obtained in plasmas under similar conditions, but without consideration of contribution of coulomb collisions. An analysis of the production of atomic hydrogen and positive ions in the plasma is also presented. This analysis shows that the densities of H3+ and H2+ are significantly lower than the densities of plasma electrons and protons