Methodology for measuring the energy characteristics of two-electrode gas discharge plasma switches in the picosecond range using the reflectometry method

Abstract

This research proposes a new technique for measuring the energy characteristics (losses of energy in the spark gap, related to light radiation, ionization, excitation, and heating of the working gas during the development of plasma; discharge power) of two-electrode gas dischargers in the subnanosecond range. The work examines the voltage waveforms across the discharge gas gap and the discharge current waveform obtained by the reflectometry method in the subnanosecond range. To do this, the traditional technique for measuring such characteristics was modified. This allows us to restore the back edge of the voltage pulse across the discharge gap at the breakdown delay and the breakdown stages, which is usually lost in the subnanosecond range when measuring such waveforms. For modification, calculated data on the ionization frequency were used. This allows us to replace the plasma of the discharge gap with a constant resistor in those sections of the voltage waveform where the characteristic ionization time is more than an order of magnitude longer than the duration of the voltage pulse applied to the gap. The waveforms of the voltage across the discharge gap and the discharge current obtained in this way allowed us to calculate the power dynamics and total energy introduced into the gas discharge plasma. These parameters are important both for calculating the efficiency of gas switches and for other applications of gas discharge plasma, in particular laser pumping.