[Background]: Due to the lack of filament lifespan limitations and electrode contamination

the high-power radio frequency (RF) ion source is the most promising ion source for achieving steady-state operation in neutral beam injection system research. During the operation of the RF ion source

dynamic variations in plasma impedance can increase reflected power

reduce RF coupling efficiency

and

in severe cases

damage core components. [Purpose]: The study aims to design a reflection protection system to address impedance mismatch and reflected power spikes in the high-power RF ion source. [Methods]: The system

based on a microcontroller

monitors reflected power in real-time using a high-precision ADC

integrates reflected power protection and spike pulse shielding functions

and achieves fast response through interrupts. A remote monitoring interface was designed using LabVIEW to enable parameter adjustment and data storage. [Results]: The test results demonstrated that the system has a maximum response delay of 150μs for protection signal output

with the spike shielding time adjustable between 10ms and 10s and 1ms precision

meeting real-time operational requirements. [Conclusions]: The proposed system ensures safe and stable operation of the high-power RF ion source

while also offering advantages such as high cost-effectiveness and easy maintenance.