Quasi-steady carbon plasma source for neutral beam injector.

Area of Science:

• Plasma Physics
• Materials Science

Background:

• Sustaining high-pressure plasmas for extended durations is challenging.
• Carrier gases are often required for plasma stability, limiting applications.

Purpose of the Study:

• To achieve long-duration carbon plasma sustainment without carrier gas.
• To investigate the use of microwave ionization and pulsed plasma injection for plasma stability.

Main Methods:

• Utilized a bucket-type ionization chamber with a cusp magnetic field.
• Employed a shunting arc plasma gun for pulsed seed plasma injection (∼3 ms duration).
• Applied 2.45 GHz microwave ionization at the electron cyclotron resonance surface.

Main Results:

• Successfully sustained carbon plasma for over 1000 seconds without carrier gas.
• Demonstrated plasma sustainment during intervals between pulsed injections.
• Showed that controlling discharge intervals maintained high pressure and long plasma duration.

Conclusions:

• Long-duration, carrier-gas-free carbon plasma can be sustained using pulsed injection and microwave ionization.
• The method offers a stable and controllable approach for generating carbon plasma.
• Potential applications in materials processing and fusion research.