On radial drift theory of ionic current to probe: II. Allowance for volume ionization in presence of collisions with atoms

The present work considers ionic current to spherical and cylindrical probes with allowance for ionization and collisions with atoms in the disturbed region of plasma. The expression describing the concentration of ions was obtained in the approximation of cold ions. The current-voltage characteristics of the probes ware calculated for a wide range of parameters (probe size, ionization frequency, and ionic free path length). Some approximate expressions were obtained for probe current-voltage curves in the extreme case of a large (plane) and a small probe.