Beam current enhancement of microwave plasma ion source utilizing double-port rectangular cavity resonator

Area of Science:

• Plasma Physics
• Microwave Engineering
• Ion Source Technology

Background:

• Microwave plasma ion sources are crucial for generating ion beams.
• Optimizing ion beam current is essential for various applications.
• Rectangular cavity resonators are used to enhance plasma generation.

Purpose of the Study:

• To investigate the effect of wave launcher type on ion beam current in a microwave plasma ion source.
• To compare the performance of single-port versus double-port wave launchers.
• To enhance the ion beam extraction capabilities of the plasma ion source.

Main Methods:

• Designed and simulated rectangular cavity resonators with single-port and double-port wave launchers using High Frequency Structure Simulator (HFSS).
• Measured microwave power for breakdown to validate resonator performance.
• Utilized Langmuir probe measurements to analyze plasma density profiles.
• Measured ion beam current to quantify performance improvements.

Main Results:

• The double-port cavity resonator, designed for TE-103 mode, demonstrated enhanced central plasma density compared to the single-port cavity (TE-102 mode).
• Ion beam current was significantly higher with the double-port resonator.
• The performance enhancement in plasma density and ion beam current increased with higher applied microwave power.

Conclusions:

• The double-port wave launcher effectively modifies plasma density profiles, leading to improved ion beam current.
• The rectangular cavity resonator with a double-port launcher shows promise for enhancing plasma ion source performance.
• This configuration is expected to improve ion beam extraction efficiency.