A co-axial electron gun to generate millimeter-wave RF using the two-stream instability

Area of Science:

• Physics
• Electrical Engineering
• Plasma Physics

Background:

• Millimeter-wave (MMW) radio frequency (RF) sources are crucial for various applications.
• Existing MMW sources often face limitations in bandwidth and power consistency.
• The two-stream instability presents a promising mechanism for novel RF generation.

Purpose of the Study:

• To design a novel broadband MMW RF source utilizing the two-stream instability.
• To achieve consistent output power over a large bandwidth from a single device.
• To optimize electron beam coupling into solenoidal magnetic fields.

Main Methods:

• Designing a device employing two co-axial, nested electron beams.
• Utilizing independently modulated cathodes for electron beam generation.
• Employing shields around cathodes to shape electric fields for enhanced beam focusing.
• Performing simulations using Trak software to predict performance.

Main Results:

• The design facilitates efficient coupling of electron beams into solenoidal magnetic fields.
• Simulations indicate the potential for consistent output power over a broad bandwidth.
• Electron beam energies are optimized within specific ranges (15-20 keV for inner, 75-95% of inner for outer).

Conclusions:

• The proposed design offers a viable path towards a novel, high-performance MMW RF source.
• The use of shaped electric fields and optimized beam energies is key to efficient operation.
• This technology has the potential to advance MMW applications requiring broadband, consistent power.