Dependence of Parameters of a Radio-Frequency Closed Electron Drift Accelerator on the Radio-Frequency Capacitive Discharge Circuit

The parameters of a radio-frequency capacitive discharge confined in a closed electron drift accelerator with an extended acceleration zone have been studied for different discharge circuits, namely, with dc-closed and dc-open electrodes and with additional dc biasing of the active electrode. In the open circuit, the plasma concentration is minimal and the ion energy in the jet at the exit from the prototype is about 25 eV. The dc closing of the active electrode increases both the plasma density and the ion energy to 250 eV. A further increase or decrease in these parameters is possible by applying a positive or negative dc bias, respectively, to the active electrode.