Non-neutral plasma manipulation techniques in development of a high-capacity positron trap

Area of Science:

• Plasma physics
• Particle confinement
• Accelerator technology

Background:

• Penning-Malmberg traps are crucial for high-density charged particle storage.
• Developing multi-cell traps is essential for scaling positron accumulation.
• Previous methods lacked efficient diagnostics and precise alignment for large ensembles.

Purpose of the Study:

• To demonstrate preliminary experiments for a multi-cell Penning-Malmberg trap.
• To introduce and validate diagnostic tools for electron plasma.
• To establish a foundation for storing large positron populations (≥10^10 e+).

Main Methods:

• Utilized a master-cell test trap with electrons for initial studies.
• Employed a phosphor screen for measuring plasma distribution and particle count.
• Applied the m=1 diocotron mode for magnetic field alignment (B=3.1 T).
• Investigated autoresonant excitation of the diocotron mode using rotating dipole fields and chirped signals.

Main Results:

• Successfully demonstrated plasma diagnostics using a phosphor screen.
• Achieved precise trap alignment to the magnetic field via diocotron mode excitation.
• Characterized plasma parameters and expansion dynamics.
• Analyzed the reproducibility of autoresonant excitation methods.

Conclusions:

• The master-cell test trap and diagnostic tools are effective for initial studies.
• Optimized excitation techniques provide a path for future multi-cell device development.
• These findings pave the way for large-scale positron storage.