High Efficiency Energy Extraction from a Relativistic Electron Beam in a Strongly Tapered Undulator

Area of Science:

• Physics
• Laser Science
• Particle Accelerators

Background:

• Development of high-power coherent radiation sources is crucial for various scientific applications.
• Efficient energy extraction from electron beams is a key challenge in accelerator physics.

Purpose of the Study:

• To demonstrate high electro-optical conversion efficiencies using a tapered helical magnetic undulator.
• To advance the development of high peak and average power coherent radiation sources.

Main Methods:

• Experimentally decelerating a 65 MeV electron beam to 35 MeV using a 200 GW CO2 laser seed.
• Utilizing a 54-cm-long strongly tapered helical magnetic undulator for energy extraction.
• Supporting experimental results with simulations of radiation field evolution.

Main Results:

• Over 30% of the initial electron beam energy was extracted to coherent radiation.
• Achieved unparalleled electro-optical conversion efficiencies for a relativistic beam in an undulator field.
• Demonstrated the effectiveness of the tapered helical magnetic undulator design.

Conclusions:

• The experiment represents a significant step towards developing advanced coherent radiation sources.
• The demonstrated conversion efficiencies highlight the potential of this method for future applications.
• Further research into undulator technology can lead to even more powerful radiation sources.