THE NONMONOTONICITY OF TRANSITION FROM FARADAY DARK SPACE TO POSITIVE-COLUMN AND THE EMERGENCE OF STANDING STRATA BEHIND THE CATHODE REGIONOF GLOW-DISCHARGE

The region of transition from the Faraday dark space to an extended ho mogeneous positive column in a glow discharge is treated. The results of analysis of the set of equations for the discharge (in a hydrodynam ic approximation) and numerical solution of the set of equations for h elium are used to demonstrate that the transition is nonmonotonic. In the general case, the nonmonotonicity exhibits the behavior of damped vibrations. However, in the absence of nonlinear ionization processes such as stepped ionization of accumulating metastable atoms, the vibra tional mode is damped so rapidly as to transform to aperiodic. A clear ly defined held maximum and a plasma density minimum appear in the tra nsition region. In the case of strong currents, when stepped ionizatio n is significant, nonlinear ionization supports the vibrational mode. The theoretically derived static strata, decaying from the cathode par t of the discharge to the anode, were observed experimentally almost h alf a century ago.