NONLINEAR CONDUCTIVITY AND COMPOSITION OF PARTIALLY-IONIZED PLASMAS IN A STRONG ELECTRIC-FIELD

A partially ionized hydrogen plasma is considered, under the influence of a strong electric field. The nonlinear electrical conductivity is calculated in a self-consistent manner from the quantum transport cros s sections of the electron-scattering processes and from a field-depen dent nonequilibrium mass-action law in order to determine the plasma c omposition. Field effects dominate the electric transport properties a t low densities because of the high ionization rates. At high densitie s, a strong increase of the conductivity describes the Mott effect cau sed by the many-body effects in the dense plasma. A minimum of the deg ree of ionization and the conductivity assign the interplay between fi eld and many-particle effects. This minimum is reinforced by the field dependence of the mass-action law.