Measuring and optimization of energy transfer to the interelectrode gaps during the synthesis of nanoparticles in a spark discharge

The problem of the efficiency of energy transfer from a capacitive energy storage device to the region of nanoparticle synthesis in a spark discharge has been considered. Using the method for measuring pulsed voltages at short gas-discharge gaps developed by the authors, the time dependence of the voltage across the active resistance of the gaps was studied for copper and titanium electrodes in different discharge regimes. For the first time, stepwise changes were observed in the time dependence of the voltage at the moments of changing the current direction. The conclusion was made about the predominant release of electrical energy in the near-electrode regions of the discharge gap, where nanoparticle synthesis occurs. For a spark discharge, the voltage across the active resistance of the interelectrode gap weakly depends on the amplitude of the flowing current and, for metal electrodes, is of the order of several tens of volts. A formula is proposed for determining the energy transferred to the discharge gap. The efficiency of energy transfer to the discharge gaps increases with increasing the quality of the discharge circuit with the use of several series-connected interelectrode gaps (in our case, from 30 to 60%), with a decrease in the capacitance or initial voltage at the capacitor. Copyright (c) 2019 American Association for Aerosol Research