Ion beamlet steering by aperture displacement for a tetrode accelerating structure

Area of Science:

• Plasma physics
• Ion beam optics
• Accelerator physics

Background:

• Precise control of ion beams is crucial for applications like particle accelerators and ion sources.
• Understanding beam steering mechanisms in accelerating structures is essential for optimizing beam quality and transport.
• Tetrode structures are commonly used for ion acceleration, but their beam steering characteristics require detailed study.

Purpose of the Study:

• To experimentally measure the steering of a single ion beamlet within a tetrode accelerating structure.
• To compare experimental steering data with predictions from a modified linear theory.
• To investigate the influence of aperture displacement and the acceleration-to-extraction voltage ratio (Gamma) on beam steering.

Main Methods:

• Experimental measurement of single ion beamlet steering in a tetrode accelerating structure.
• Systematic variation of aperture displacement and the voltage ratio (Gamma).
• Comparison of experimental results with theoretical predictions from a modified linear theory.

Main Results:

• Experimental data confirmed predicted features: null steering at a specific Gamma and a directional steering change.
• Observed significant nonlinear steering behavior not fully captured by the modified linear theory.
• Identified a specific Gamma value for null steering, indicating a control point for beam trajectory.

Conclusions:

• The study demonstrates that while linear theory captures some aspects of ion beamlet steering, nonlinear effects are significant in tetrode structures.
• The observed nonlinearity has implications for the precise control and focusing of ion beams in multibeamlet sources.
• Further theoretical development is needed to accurately model the nonlinear steering phenomena for improved accelerator design.