A. A. Bogomaz

Multipulse discharge in the chamber of electric discharge launcher

The investigation results of an electric discharge launchers (EDL) chamber operation at hydrogen initial pressure 20-40 MPa, discharge current 0.5-1.0 MA, current rise rate (0.5-1.0)/spl times/10/sup 10/ A/s and input energy up to 2.2 MJ are presented. The coaxial electrode system consists of cylindrical anode and conic cathode. The discharge is initiated by copper wire in the interelectrode gap of 0.8-2.5 mm. The conditions of multipulse discharge current appearance, at the pulses number 5-15 (in comparison with usual multipulse regime 2-3 pulses), amplitude 0.5-1.0 MA and single pulse duration 50-200 /spl mu/s, are determined. The speeds of arc movement (1.5-3.0 km/s) and arc channel expansion (0.2-0.4 km/s), were measured by means of high-speed camera. The efficiency of energy transfer from the power supply (capacitor storage) to the arc was about 85% and from the arc to gas-90%. Electrodes erosion was found to be 30-40% less compared with usual multipulse regime. Besides the anode and cathode, total erosion was 30-40 mg/C at passed charge up to 800 C. The results estimation of different mechanisms contribution to heat transfer from the arc to surrounding hydrogen are discussed. It was shown that both repeated dissipation of arc plasma internal energy after arc extinction and the shock waves, appearing at the breakdowns of interelectrode gap, increase the efficiency of gas heating. It was proposed that decreasing of electrodes erosion at the multipulse regime is connected both with the growth of electrode spots movement speed and with the decreasing of current amplitude from 1.5-2.0 MA (usual multipulse regime) to 1.0 MA.

Influence of the cathode and anode jets on the properties of a high-current electric arc

AbstractA study is made of the effects related to the formation of electrode jets in discharges in hydrogen and air at a current of 105–106 A, a current growth rate of 1010 A/s, an initial pressure of 0.1–4.0 MPa, and a discharge gap length of 5–40 mm. After secondary breakdown, jets are observed in a semitransparent discharge channel expanding with a velocity of (4–7)×102 m/s. The formation of shock waves in the interaction of the jets with the ambient gas and the opposite electrode is observed by the shadowgraphy method. Seventy microseconds after the beginning of the discharge, the pressure of the metal vapor plasma near the end of the tungsten cathode amounts to 177 MPa. The brightness temperature in this case is T=59×103 K, the average ion charge number is

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

\overline m = 3.1

Detection of X rays from a high-current discharge in a dense gaseous medium

, and the metal vapor density is n=5.3×1019 cm−3. After 90 µs, the average ion charge number and the metal vapor density near the anode end are

Electrode Plasma Jets in Powerful Pulsed Discharge in High-Pressure Gas

\overline m = 2.6

Electric discharge parameters in high density gas

and n=7.4×1019 cm−3, respectively. Based on the experimental data, possible reasons for the abnormally high values of the total voltage drop near the electrodes (up to ∼1 kV) are discussed.