Backbreakdown phenomenon in low current discharge at atmospheric pressure in transversal flow

One of the main challenges of modern plasma chemistry is to develop a power ful and high pressure discharge generating a non equilibrium cold plasma fo r chemical applications. Intermediate discharges between hot quasi equilibr ium plasma and cold non equilibrium plasma are subjected to a new interest. For various applications, the behaviour of the discharge is determined mai nly by processes of high temperature column of plasma interaction with cold gas flow. It means that hydrodynamic processes play a significant role and strong interaction of high temperature discharge with cold,gas flow must b e taken into account. In order to study such an interaction we performed ex periments in which anode and cathode spots remained fixed at the tips of el ectrodes. In these conditions it is very easy to determine the characterist ics of the discharge motion. One of most important experimental result is t he so called: back-breakdown phenomenon. Then it is possible to express the motion of the discharge as a function physical parameters of the ionised g as. A simple model of interaction is introduced which allows a better under standing of various chemical reactors.