Surface plasma source with saddle antenna radio frequency plasma generator.

Area of Science:

• Plasma Physics
• Ion Source Technology
• Particle Accelerator Components

Background:

• Development of efficient and reliable ion sources is crucial for particle accelerators and fusion research.
• Existing radio frequency (RF) surface plasma sources (SPS) face challenges in power efficiency and beam quality.
• The need for improved performance in H(-) ion beam generation necessitates novel antenna and chamber designs.

Purpose of the Study:

• To develop and test a prototype RF H(-) surface plasma source (SPS) utilizing a saddle (SA) RF antenna.
• To evaluate the power efficiency, beam brightness, lifetime, and reliability of the new SA SPS design.
• To compare the performance of the SA SPS with existing RF antenna configurations in H(-) beam generation.

Main Methods:

• Fabrication and testing of several plasma generator versions with small aluminum nitride (AlN) discharge chambers, different antennas, and magnetic field configurations.
• Installation and operation of a prototype SA SPS with a larger AlN chamber in the Spallation Neutron Source (SNS) ion source test stand.
• Conducting control experiments using H(-) beams produced by SNS SPS with internal and external antennas.

Main Results:

• The prototype SA SPS achieved unanalyzed peak currents of up to 67 mA.
• An apparent efficiency of up to 1.6 mA/kW was recorded, indicating improved power efficiency.
• A new version of the RF triggering plasma gun was designed, and a water-cooled saddle antenna SPS was fabricated for high duty factor testing.

Conclusions:

• The saddle antenna RF H(-) surface plasma source (SPS) shows significant potential for enhanced power efficiency and beam characteristics.
• The developed SA SPS design offers improved reliability and lifetime, suitable for high pulsed and average current applications.
• Further testing with a water-cooled system is planned to assess performance at high duty factors.