A New Ion Extraction Method—Radio Frequency Resonance Method

In conventional ion extraction using an electrostatic field, the plasma shield effect limits the ion extraction time and the ion extraction efficiency. A new method using an radio frequency (RF) resonance has been proposed to decrease the influence of the plasma shield effect. This method uses the relation between the RF field and the impedance of the plasma circle. When the RF frequency is swept, the resonance of the RF field and the plasma occurs at a certain frequency, thus the impedance of the plasma becomes the minimum. The electric field penetrates the plasma, and the ion extraction efficiency is raised. The RF method shortens the ion extraction time, and increases the ion extraction efficiency. It can also control the plasma density by changing the magnetic field. This article introduces the simulation calculation and the experimental research of this new method.