Significance of generalized critical velocities in collisional gas discharges in particular reference to critical velocity diagrams with partially and fully ionized regimes

Summary form only given, as follows. This paper concerns further developments of a generalization of critical velocity concept to neutral, plasma or charged particles and beams in neutral and/or partially ionized collisional gases. While such a generalized critical velocity concept is considered an extension of Alfven´s critical velocity for almost collisionless counter-streaming neutral and plasma beams, the concept is capable for understanding all the phases of ionization processes, namely streamer, leader advancement, discharge channel formation, and a final main discharge, thus making a unified view of gas discharges possible.