Characteristic of discharge at parameters of lightning channel

In this paper the parameters of the plasma of the high power electric discharge at the atmospheric pressure are presented. The discharge is characterized by total electric charge ≈100 C, by the average current 300 A and by the total duration of the discharge a few hundreds ms. Before the breakdown the electrodes with distance of 40 cm were connected with the wire of 300 μm diameter. For diagnostics the digital camera with 2000 pictures per second and exposition of 5 μs and a spectrometer Mechelle in visible range of radiation were used. The current channel is composed from two parts. The first, connected with the electrodes, is directed straight to another electrode and it has total length 20 cm. It is characterized with high illumination and thermal plasma with Spitzer conductivity. The second part connecting the ends of the first part is characterized with non-ideal plasma, fast transforming direction and wide range of illumination, diameters (1÷30 mm), temperatures (0.1 ÷ 1 eV) and plasma densities (10²⁴÷10²⁵ m^-3). In this part the narrow and bright channels were observed with high conductivity two orders higher than the Spitzer conductivity.