Investigation of Dependence of Power Transfer on Frequency in the Linac4 Negative Hydrogen Ion Source

Abstract

Linac4 is radio frequency (RF) driven type negative hydrogen H⁻ ion source. In the RF system, it is required to match the impedance between the RF-system and plasma loading. In order to match the impedance, it is essential to analyze the plasma impedance. In this study, we analyze the dependence of power transfer on the input parameters (frequency, input power and H₂ gas pressure) by using the plasma impedance prediction model. The results indicate that in the case of frequency = 2 MHz, which is often used in the experiment, efficient power supply is seen in the wide range of input power and H₂ gas pressure. Also, if the optimum value of input power and H₂ gas pressure is input, it may be possible to reduce the influence of the frequency value on the power reflection efficiency.