RF-driven ion source for accelerator mass spectrometry with plasma modeling and validation test stand

A duoplasmatron, an ion source typically used in accelerator mass spectrometry, was tested at Dongguk University, Korea, within its radiocarbon dating facility that incorporates a mini carbon dating system. The facility developed a prototype ion source for analyzing high-level 14 C samples. However, the duoplasmatron exhibits limitations in terms of reliability and efficiency when used for carbon counting in gas samples. To address these limitations of duoplasmatron with plasma persistence and filament lifetime, a reliable and low-maintenance RF-driven ion source was proposed, designed and fabricated. This study focuses on plasma modeling within the RF ion source to facilitate simulation studies and predict plasma conditions. An RF ion source test stand was installed, enabling the direct injection of CO 2 gas to verify the performance of RF components and confirm plasma ignition. RGA scanning revealed the elemental species generated during the plasma ignition, indicating an increase in the relative pressure intensity of the target elements. The results of the RF ion source plasma simulations and the test stand validation through a residual gas analysis, comparing the simulation and RGA scanning results are presented in this paper. • Simulations were performed with carbon dioxide plasma using COMSOL code. • 200 MHz 500 W RF solid-state power amplifiers were fabricated for RF ion source test stand. • An RF test was conducted to determine the operation and first plasma ignition were observed. • An RGA scanning experiment was conducted to identify the gas ion species generated during plasma ignition.