Characteristic features of formation of shock waves under conditions of discharge in argon in external magnetic field

The effect of magnetic field on the expansion of spark channel and on the formation of shock wave is considered. It is demonstrated that the expansion in the initial stage of discharge occurs in almost the isothermal mode, where the temperature of channel plasma decreases insignificantly (by $10$–$15\%$) during the first $300$ nanoseconds. The presence of longitudinal magnetic field results in an abrupt decrease in the rate of expansion of channel and in an increase in the plasma temperature.