Study of Spark Discharge in Ground at Lightning Current Pulse Reproduction using MCG

According to developed electric power magneto-cumulative generators are the facilities most close to a current discharge of natural lightning with the current pulse amplitude of 100-200 kA. High power intensity of the magneto-cumulative generators - tens megajoules of a magnetic energy - makes it possible to study effect of the lightning current pulses on different objects of civilian or military purposes. The paper presents investigation results of the spark discharge development from the vertical grounding rod in a soil with specific conductivity of ~10² cm/in at current pulse reproduction on it with the amplitude up to 70 kA. Formation and development of multiple spark channels on the ground having the maximum length of more than 30 m was recorded for the first time in the range of optical wave length. In mis case the maximum value of the potential pulse on the grounding rod did not exceed 400 kV. Volt-ampere characteristics of the current pulse, formed in the grounding rod, and distribution of electric potentials near it are presented in the paper.