Active Plasma Lensing for Relativistic Laser-Plasma-Accelerated Electron Beams

Area of Science:

• Plasma physics
• Accelerator physics
• Laser-plasma interactions

Background:

• Compact, tunable, radially symmetric focusing of electrons is critical for laser-plasma accelerator (LPA) applications.
• Existing focusing methods may not meet the requirements for compactness and tunability needed in advanced LPA applications.

Purpose of the Study:

• To demonstrate the effectiveness of a discharge-capillary active plasma lens for focusing electron beams from LPAs.
• To characterize the focusing performance, including tunable field gradients and focal lengths.

Main Methods:

• Experimental demonstration using a discharge-capillary active plasma lens.
• Focusing of 100-MeV-level LPA electron beams.
• Measurement of tunable field gradients exceeding 3000 T/m.

Main Results:

• Successful focusing of LPA electron beams was achieved.
• The plasma lens provided tunable field gradients over 3000 T/m.
• Achieved cm-scale focal lengths for GeV-level beam energies, maintaining compact accelerator footprints.
• Excellent agreement between experimental results and simulations was observed across various lens strengths.

Conclusions:

• The discharge-capillary active plasma lens is a viable technology for focusing LPA electron beams.
• This lens enables compact and tunable focusing, essential for advancing LPA applications.
• The technology supports the development of compact electron beams and light sources derived from LPAs.