Investigation of anode and jets influence on electric arc properties with current up to 500kA

A number of phenomena connected with formation of electrode jets in discharges with current strength 10/sup 5/-10/sup 6/ A, at rate of its rise of 10/sup 10/ A/s in hydrogen and air at initial pressure 0.1-4.0 MPa and length of discharge gap 5-40 mm. After the secondary breakdown the jets are observed through the discharge semi-transparent channel, widening with a velocity (4-7)/spl middot/10/sup 2/ m/s. Shock waves formation was detected at interaction of jets with surrounding gas and the opposite electrode by a shadow method. Pressure of plasma vapors of metal near to the end of the tungsten cathode in 70 /spl mu/s after initiation of a discharge was 177 MPa. Thus magnitude of brightness temperature was 59-10/sup 3/ K, average charge of ions - m~=3.1, and concentration of metal vapors n=5.3/spl middot/10/sup 19/ cm/sup -3/. At the end of the anode in 90 /spl mu/s m~=2.6, a n=7.4/spl middot/10/sup 19/ cm/sup -3/. Probable reasons of anomalous high voltage drops near the electrodes, the summarized magnitude of which is /spl sim/1 kV are discussed on the basis of experimental data.