Note: development of ESS Bilbao's proton ion source: Ion Source Hydrogen positive

Area of Science:

• Plasma Physics
• Ion Source Technology
• Microwave Discharges

Background:

• The development of reliable ion sources is crucial for various scientific and industrial applications.
• Existing off-resonance microwave discharge ion sources face challenges with magnetic field stability and source reliability.
• Electron Cyclotron Resonance (ECR) fields are commonly used, but off-resonance operation presents unique design considerations.

Purpose of the Study:

• To design and implement a novel magnetic system for a 2.7 GHz hydrogen positive ion source.
• To enhance the reliability and performance of the ion source through improved magnetic field generation.
• To validate the magnetic system design using simulations and experimental measurements.

Main Methods:

• Utilized a 2.7 GHz off-resonance microwave discharge plasma chamber.
• Designed a new magnetic system combining four coils and soft iron to generate an axial magnetic field exceeding the ECR resonance field (approx. 0.1 T).
• Performed magnetic field simulations and compared them with experimental magnetic measurements.
• Conducted initial commissioning tests with extraction voltages up to 50 kV.

Main Results:

• A new magnetic system integrating coils and soft iron was successfully designed and implemented.
• Simulations of the magnetic field were performed and validated against experimental measurements.
• The ion source demonstrated reliable operation during initial commissioning tests up to 50 kV extraction voltage.

Conclusions:

• The novel magnetic system significantly enhances the reliability of the hydrogen positive ion source.
• The design approach combining simulations and experimental validation is effective for optimizing ion source performance.
• The source is suitable for applications requiring high-voltage ion extraction.