A multibeam radio-frequency ion source with a discharge chamber inside a resonator

The design of a multibeam ion source with a discharge chamber inside a half-wavelength radio-frequency (RF) resonator with a spiral load is described. The resonator is excited by a loop insulated from the body of the resonator. The RF oscillator operating at a frequency of 38 MHz is grounded. The use of the resonator facilitates the initiation of a discharge at a low power level. The amplitude-frequency characteristics of the resonator at the operating frequencies of the ion source are presented. The effect of the RF power and the extracting voltage on the ion-beam current has been studied. The experimental results on the ion-beam extraction at a low RF power (