Energy Characteristics of Self-Sustained Subnanosecond Discharge in Hydrogen

In a wide range of pressures (10–60 atm) the energy characteristics (losses of the switched energy in the spark gap, which go to light emission, ionization, excitation and heating of the working gas during the development of plasma processes; as well as the instantaneous released power, which serves as an energy source for the above processes) of two-electrode hydrogen spark gaps of the subnanosecond range are investigated. The influence of runaway electrons on the energy characteristics of hydrogen switches is investigated. For these purposes, a modification of the reflectometry method for measuring pulse voltages in the study of subnanosecond self-sustained discharges in gas is proposed. It consists in the fact that the resistance of the plasma of the discharge gas gap, changing in time at the switching stage, is replaced by a constant resistor in those sections of the voltage oscillogram, where the characteristic ionization time exceeds the duration of the voltage pulse applied to the gap by more than an order of magnitude. This made it possible to reconstruct the trailing edge of the voltage pulse on the discharge gap, measured at the breakdown delay and breakdown stages, which is usually lost in the subnanosecond range when measuring such oscillograms due to the presence of parasitic inductance of the measuring path. The voltage and current oscillograms obtained in this way allowed us to calculate the dynamics of the power and the total energy introduced into the gas-discharge plasma.